November 2022 - Linux-stable-mirror

FAILED: patch "[PATCH] KVM: SVM: retrieve VMCB from assembly" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. Possible dependencies: f6d58266d731 ("KVM: SVM: retrieve VMCB from assembly") f7ef280132f9 ("KVM: SVM: adjust register allocation for __svm_vcpu_run()") 16fdc1de169e ("KVM: SVM: replace regs argument of __svm_vcpu_run() with vcpu_svm") debc5a1ec0d1 ("KVM: x86: use a separate asm-offsets.c file") bb06650634d3 ("KVM: VMX: Convert launched argument to flags") 8bd200d23ec4 ("KVM: VMX: Flatten __vmx_vcpu_run()") 527a534c7326 ("x86/tdx: Provide common base for SEAMCALL and TDCALL C wrappers") 59bd54a84d15 ("x86/tdx: Detect running as a TDX guest in early boot") 6198311093da ("x86/cc: Move arch/x86/{kernel/cc_platform.c => coco/core.c}") f94909ceb1ed ("x86: Prepare asm files for straight-line-speculation") 22da5a07c75e ("x86/lib/atomic64_386_32: Rename things") 1367afaa2ee9 ("x86/entry: Use the correct fence macro after swapgs in kernel CR3") c07e45553da1 ("x86/entry: Add a fence for kernel entry SWAPGS in paranoid_entry()") 6e5772c8d9cf ("Merge tag 'x86_cc_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From f6d58266d731fd7e63163790aad21e0dbb1d5264 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini <pbonzini(a)redhat.com> Date: Mon, 7 Nov 2022 04:17:29 -0500 Subject: [PATCH] KVM: SVM: retrieve VMCB from assembly Continue moving accesses to struct vcpu_svm to vmenter.S. Reducing the number of arguments limits the chance of mistakes due to different registers used for argument passing in 32- and 64-bit ABIs; pushing the VMCB argument and almost immediately popping it into a different register looks pretty weird. 32-bit ABI is not a concern for __svm_sev_es_vcpu_run() which is 64-bit only; however, it will soon need @svm to save/restore SPEC_CTRL so stay consistent with __svm_vcpu_run() and let them share the same prototype. No functional change intended. Cc: stable(a)vger.kernel.org Fixes: a149180fbcf3 ("x86: Add magic AMD return-thunk") Reviewed-by: Sean Christopherson <seanjc(a)google.com> Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> diff --git a/arch/x86/kvm/kvm-asm-offsets.c b/arch/x86/kvm/kvm-asm-offsets.c index 30db96852e2d..f1b694e431ae 100644 --- a/arch/x86/kvm/kvm-asm-offsets.c +++ b/arch/x86/kvm/kvm-asm-offsets.c @@ -15,6 +15,8 @@ static void __used common(void) if (IS_ENABLED(CONFIG_KVM_AMD)) { BLANK(); OFFSET(SVM_vcpu_arch_regs, vcpu_svm, vcpu.arch.regs); + OFFSET(SVM_current_vmcb, vcpu_svm, current_vmcb); + OFFSET(KVM_VMCB_pa, kvm_vmcb_info, pa); } if (IS_ENABLED(CONFIG_KVM_INTEL)) { diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index b412bc5773c5..0c86c435c51f 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -3914,12 +3914,11 @@ static fastpath_t svm_exit_handlers_fastpath(struct kvm_vcpu *vcpu) static noinstr void svm_vcpu_enter_exit(struct kvm_vcpu *vcpu) { struct vcpu_svm *svm = to_svm(vcpu); - unsigned long vmcb_pa = svm->current_vmcb->pa; guest_state_enter_irqoff(); if (sev_es_guest(vcpu->kvm)) { - __svm_sev_es_vcpu_run(vmcb_pa); + __svm_sev_es_vcpu_run(svm); } else { struct svm_cpu_data *sd = per_cpu(svm_data, vcpu->cpu); @@ -3930,7 +3929,7 @@ static noinstr void svm_vcpu_enter_exit(struct kvm_vcpu *vcpu) * vmcb02 when switching vmcbs for nested virtualization. */ vmload(svm->vmcb01.pa); - __svm_vcpu_run(vmcb_pa, svm); + __svm_vcpu_run(svm); vmsave(svm->vmcb01.pa); vmload(__sme_page_pa(sd->save_area)); diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index 447e25c9101a..7ff1879e73c5 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -683,7 +683,7 @@ void sev_es_unmap_ghcb(struct vcpu_svm *svm); /* vmenter.S */ -void __svm_sev_es_vcpu_run(unsigned long vmcb_pa); -void __svm_vcpu_run(unsigned long vmcb_pa, struct vcpu_svm *svm); +void __svm_sev_es_vcpu_run(struct vcpu_svm *svm); +void __svm_vcpu_run(struct vcpu_svm *svm); #endif diff --git a/arch/x86/kvm/svm/vmenter.S b/arch/x86/kvm/svm/vmenter.S index 531510ab6072..d07bac1952c5 100644 --- a/arch/x86/kvm/svm/vmenter.S +++ b/arch/x86/kvm/svm/vmenter.S @@ -32,7 +32,6 @@ /** * __svm_vcpu_run - Run a vCPU via a transition to SVM guest mode - * @vmcb_pa: unsigned long * @svm: struct vcpu_svm * */ SYM_FUNC_START(__svm_vcpu_run) @@ -49,16 +48,16 @@ SYM_FUNC_START(__svm_vcpu_run) push %_ASM_BX /* Save @svm. */ - push %_ASM_ARG2 - - /* Save @vmcb. */ push %_ASM_ARG1 +.ifnc _ASM_ARG1, _ASM_DI /* Move @svm to RDI. */ - mov %_ASM_ARG2, %_ASM_DI + mov %_ASM_ARG1, %_ASM_DI +.endif - /* "POP" @vmcb to RAX. */ - pop %_ASM_AX + /* Get svm->current_vmcb->pa into RAX. */ + mov SVM_current_vmcb(%_ASM_DI), %_ASM_AX + mov KVM_VMCB_pa(%_ASM_AX), %_ASM_AX /* Load guest registers. */ mov VCPU_RCX(%_ASM_DI), %_ASM_CX @@ -170,7 +169,7 @@ SYM_FUNC_END(__svm_vcpu_run) /** * __svm_sev_es_vcpu_run - Run a SEV-ES vCPU via a transition to SVM guest mode - * @vmcb_pa: unsigned long + * @svm: struct vcpu_svm * */ SYM_FUNC_START(__svm_sev_es_vcpu_run) push %_ASM_BP @@ -185,8 +184,9 @@ SYM_FUNC_START(__svm_sev_es_vcpu_run) #endif push %_ASM_BX - /* Move @vmcb to RAX. */ - mov %_ASM_ARG1, %_ASM_AX + /* Get svm->current_vmcb->pa into RAX. */ + mov SVM_current_vmcb(%_ASM_ARG1), %_ASM_AX + mov KVM_VMCB_pa(%_ASM_AX), %_ASM_AX /* Enter guest mode */ sti

2 years, 1 month

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FAILED: patch "[PATCH] KVM: SVM: adjust register allocation for __svm_vcpu_run()" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. Possible dependencies: f7ef280132f9 ("KVM: SVM: adjust register allocation for __svm_vcpu_run()") 16fdc1de169e ("KVM: SVM: replace regs argument of __svm_vcpu_run() with vcpu_svm") debc5a1ec0d1 ("KVM: x86: use a separate asm-offsets.c file") bb06650634d3 ("KVM: VMX: Convert launched argument to flags") 8bd200d23ec4 ("KVM: VMX: Flatten __vmx_vcpu_run()") 527a534c7326 ("x86/tdx: Provide common base for SEAMCALL and TDCALL C wrappers") 59bd54a84d15 ("x86/tdx: Detect running as a TDX guest in early boot") 6198311093da ("x86/cc: Move arch/x86/{kernel/cc_platform.c => coco/core.c}") f94909ceb1ed ("x86: Prepare asm files for straight-line-speculation") 22da5a07c75e ("x86/lib/atomic64_386_32: Rename things") 1367afaa2ee9 ("x86/entry: Use the correct fence macro after swapgs in kernel CR3") c07e45553da1 ("x86/entry: Add a fence for kernel entry SWAPGS in paranoid_entry()") 6e5772c8d9cf ("Merge tag 'x86_cc_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From f7ef280132f9bf6f82acf5aa5c3c837206eef501 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini <pbonzini(a)redhat.com> Date: Fri, 28 Oct 2022 17:30:07 -0400 Subject: [PATCH] KVM: SVM: adjust register allocation for __svm_vcpu_run() 32-bit ABI uses RAX/RCX/RDX as its argument registers, so they are in the way of instructions that hardcode their operands such as RDMSR/WRMSR or VMLOAD/VMRUN/VMSAVE. In preparation for moving vmload/vmsave to __svm_vcpu_run(), keep the pointer to the struct vcpu_svm in %rdi. In particular, it is now possible to load svm->vmcb01.pa in %rax without clobbering the struct vcpu_svm pointer. No functional change intended. Cc: stable(a)vger.kernel.org Fixes: a149180fbcf3 ("x86: Add magic AMD return-thunk") Reviewed-by: Sean Christopherson <seanjc(a)google.com> Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> diff --git a/arch/x86/kvm/svm/vmenter.S b/arch/x86/kvm/svm/vmenter.S index f0ff41103e4c..531510ab6072 100644 --- a/arch/x86/kvm/svm/vmenter.S +++ b/arch/x86/kvm/svm/vmenter.S @@ -54,29 +54,29 @@ SYM_FUNC_START(__svm_vcpu_run) /* Save @vmcb. */ push %_ASM_ARG1 - /* Move @svm to RAX. */ - mov %_ASM_ARG2, %_ASM_AX + /* Move @svm to RDI. */ + mov %_ASM_ARG2, %_ASM_DI + + /* "POP" @vmcb to RAX. */ + pop %_ASM_AX /* Load guest registers. */ - mov VCPU_RCX(%_ASM_AX), %_ASM_CX - mov VCPU_RDX(%_ASM_AX), %_ASM_DX - mov VCPU_RBX(%_ASM_AX), %_ASM_BX - mov VCPU_RBP(%_ASM_AX), %_ASM_BP - mov VCPU_RSI(%_ASM_AX), %_ASM_SI - mov VCPU_RDI(%_ASM_AX), %_ASM_DI + mov VCPU_RCX(%_ASM_DI), %_ASM_CX + mov VCPU_RDX(%_ASM_DI), %_ASM_DX + mov VCPU_RBX(%_ASM_DI), %_ASM_BX + mov VCPU_RBP(%_ASM_DI), %_ASM_BP + mov VCPU_RSI(%_ASM_DI), %_ASM_SI #ifdef CONFIG_X86_64 - mov VCPU_R8 (%_ASM_AX), %r8 - mov VCPU_R9 (%_ASM_AX), %r9 - mov VCPU_R10(%_ASM_AX), %r10 - mov VCPU_R11(%_ASM_AX), %r11 - mov VCPU_R12(%_ASM_AX), %r12 - mov VCPU_R13(%_ASM_AX), %r13 - mov VCPU_R14(%_ASM_AX), %r14 - mov VCPU_R15(%_ASM_AX), %r15 + mov VCPU_R8 (%_ASM_DI), %r8 + mov VCPU_R9 (%_ASM_DI), %r9 + mov VCPU_R10(%_ASM_DI), %r10 + mov VCPU_R11(%_ASM_DI), %r11 + mov VCPU_R12(%_ASM_DI), %r12 + mov VCPU_R13(%_ASM_DI), %r13 + mov VCPU_R14(%_ASM_DI), %r14 + mov VCPU_R15(%_ASM_DI), %r15 #endif - - /* "POP" @vmcb to RAX. */ - pop %_ASM_AX + mov VCPU_RDI(%_ASM_DI), %_ASM_DI /* Enter guest mode */ sti

2 years, 1 month

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FAILED: patch "[PATCH] KVM: SVM: adjust register allocation for __svm_vcpu_run()" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. Possible dependencies: f7ef280132f9 ("KVM: SVM: adjust register allocation for __svm_vcpu_run()") 16fdc1de169e ("KVM: SVM: replace regs argument of __svm_vcpu_run() with vcpu_svm") debc5a1ec0d1 ("KVM: x86: use a separate asm-offsets.c file") bb06650634d3 ("KVM: VMX: Convert launched argument to flags") 8bd200d23ec4 ("KVM: VMX: Flatten __vmx_vcpu_run()") 527a534c7326 ("x86/tdx: Provide common base for SEAMCALL and TDCALL C wrappers") 59bd54a84d15 ("x86/tdx: Detect running as a TDX guest in early boot") 6198311093da ("x86/cc: Move arch/x86/{kernel/cc_platform.c => coco/core.c}") f94909ceb1ed ("x86: Prepare asm files for straight-line-speculation") 22da5a07c75e ("x86/lib/atomic64_386_32: Rename things") 1367afaa2ee9 ("x86/entry: Use the correct fence macro after swapgs in kernel CR3") c07e45553da1 ("x86/entry: Add a fence for kernel entry SWAPGS in paranoid_entry()") 6e5772c8d9cf ("Merge tag 'x86_cc_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From f7ef280132f9bf6f82acf5aa5c3c837206eef501 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini <pbonzini(a)redhat.com> Date: Fri, 28 Oct 2022 17:30:07 -0400 Subject: [PATCH] KVM: SVM: adjust register allocation for __svm_vcpu_run() 32-bit ABI uses RAX/RCX/RDX as its argument registers, so they are in the way of instructions that hardcode their operands such as RDMSR/WRMSR or VMLOAD/VMRUN/VMSAVE. In preparation for moving vmload/vmsave to __svm_vcpu_run(), keep the pointer to the struct vcpu_svm in %rdi. In particular, it is now possible to load svm->vmcb01.pa in %rax without clobbering the struct vcpu_svm pointer. No functional change intended. Cc: stable(a)vger.kernel.org Fixes: a149180fbcf3 ("x86: Add magic AMD return-thunk") Reviewed-by: Sean Christopherson <seanjc(a)google.com> Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> diff --git a/arch/x86/kvm/svm/vmenter.S b/arch/x86/kvm/svm/vmenter.S index f0ff41103e4c..531510ab6072 100644 --- a/arch/x86/kvm/svm/vmenter.S +++ b/arch/x86/kvm/svm/vmenter.S @@ -54,29 +54,29 @@ SYM_FUNC_START(__svm_vcpu_run) /* Save @vmcb. */ push %_ASM_ARG1 - /* Move @svm to RAX. */ - mov %_ASM_ARG2, %_ASM_AX + /* Move @svm to RDI. */ + mov %_ASM_ARG2, %_ASM_DI + + /* "POP" @vmcb to RAX. */ + pop %_ASM_AX /* Load guest registers. */ - mov VCPU_RCX(%_ASM_AX), %_ASM_CX - mov VCPU_RDX(%_ASM_AX), %_ASM_DX - mov VCPU_RBX(%_ASM_AX), %_ASM_BX - mov VCPU_RBP(%_ASM_AX), %_ASM_BP - mov VCPU_RSI(%_ASM_AX), %_ASM_SI - mov VCPU_RDI(%_ASM_AX), %_ASM_DI + mov VCPU_RCX(%_ASM_DI), %_ASM_CX + mov VCPU_RDX(%_ASM_DI), %_ASM_DX + mov VCPU_RBX(%_ASM_DI), %_ASM_BX + mov VCPU_RBP(%_ASM_DI), %_ASM_BP + mov VCPU_RSI(%_ASM_DI), %_ASM_SI #ifdef CONFIG_X86_64 - mov VCPU_R8 (%_ASM_AX), %r8 - mov VCPU_R9 (%_ASM_AX), %r9 - mov VCPU_R10(%_ASM_AX), %r10 - mov VCPU_R11(%_ASM_AX), %r11 - mov VCPU_R12(%_ASM_AX), %r12 - mov VCPU_R13(%_ASM_AX), %r13 - mov VCPU_R14(%_ASM_AX), %r14 - mov VCPU_R15(%_ASM_AX), %r15 + mov VCPU_R8 (%_ASM_DI), %r8 + mov VCPU_R9 (%_ASM_DI), %r9 + mov VCPU_R10(%_ASM_DI), %r10 + mov VCPU_R11(%_ASM_DI), %r11 + mov VCPU_R12(%_ASM_DI), %r12 + mov VCPU_R13(%_ASM_DI), %r13 + mov VCPU_R14(%_ASM_DI), %r14 + mov VCPU_R15(%_ASM_DI), %r15 #endif - - /* "POP" @vmcb to RAX. */ - pop %_ASM_AX + mov VCPU_RDI(%_ASM_DI), %_ASM_DI /* Enter guest mode */ sti

2 years, 1 month

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FAILED: patch "[PATCH] KVM: SVM: move MSR_IA32_SPEC_CTRL save/restore to assembly" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. Possible dependencies: 9f2febf3f04d ("KVM: SVM: move MSR_IA32_SPEC_CTRL save/restore to assembly") e287bd005ad9 ("KVM: SVM: restore host save area from assembly") e61ab42de874 ("KVM: SVM: move guest vmsave/vmload back to assembly") 73412dfeea72 ("KVM: SVM: do not allocate struct svm_cpu_data dynamically") 181d0fb0bb02 ("KVM: SVM: remove dead field from struct svm_cpu_data") f6d58266d731 ("KVM: SVM: retrieve VMCB from assembly") f7ef280132f9 ("KVM: SVM: adjust register allocation for __svm_vcpu_run()") 16fdc1de169e ("KVM: SVM: replace regs argument of __svm_vcpu_run() with vcpu_svm") debc5a1ec0d1 ("KVM: x86: use a separate asm-offsets.c file") 07853adc29a0 ("KVM: VMX: Prevent RSB underflow before vmenter") fc02735b14ff ("KVM: VMX: Prevent guest RSB poisoning attacks with eIBRS") bb06650634d3 ("KVM: VMX: Convert launched argument to flags") 8bd200d23ec4 ("KVM: VMX: Flatten __vmx_vcpu_run()") acac5e98ef8d ("x86/speculation: Remove x86_spec_ctrl_mask") bbb69e8bee1b ("x86/speculation: Use cached host SPEC_CTRL value for guest entry/exit") 7c693f54c873 ("x86/speculation: Add spectre_v2=ibrs option to support Kernel IBRS") c779bc1a9002 ("x86/bugs: Optimize SPEC_CTRL MSR writes") caa0ff24d5d0 ("x86/bugs: Keep a per-CPU IA32_SPEC_CTRL value") a149180fbcf3 ("x86: Add magic AMD return-thunk") d9e9d2300681 ("x86,objtool: Create .return_sites") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 9f2febf3f04daebdaaa5a43cfa20e3844905c0f9 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini <pbonzini(a)redhat.com> Date: Fri, 30 Sep 2022 14:24:40 -0400 Subject: [PATCH] KVM: SVM: move MSR_IA32_SPEC_CTRL save/restore to assembly Restoration of the host IA32_SPEC_CTRL value is probably too late with respect to the return thunk training sequence. With respect to the user/kernel boundary, AMD says, "If software chooses to toggle STIBP (e.g., set STIBP on kernel entry, and clear it on kernel exit), software should set STIBP to 1 before executing the return thunk training sequence." I assume the same requirements apply to the guest/host boundary. The return thunk training sequence is in vmenter.S, quite close to the VM-exit. On hosts without V_SPEC_CTRL, however, the host's IA32_SPEC_CTRL value is not restored until much later. To avoid this, move the restoration of host SPEC_CTRL to assembly and, for consistency, move the restoration of the guest SPEC_CTRL as well. This is not particularly difficult, apart from some care to cover both 32- and 64-bit, and to share code between SEV-ES and normal vmentry. Cc: stable(a)vger.kernel.org Fixes: a149180fbcf3 ("x86: Add magic AMD return-thunk") Suggested-by: Jim Mattson <jmattson(a)google.com> Reviewed-by: Sean Christopherson <seanjc(a)google.com> Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index da7c361f47e0..6ec0b7ce7453 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -196,22 +196,15 @@ void __init check_bugs(void) } /* - * NOTE: This function is *only* called for SVM. VMX spec_ctrl handling is - * done in vmenter.S. + * NOTE: This function is *only* called for SVM, since Intel uses + * MSR_IA32_SPEC_CTRL for SSBD. */ void x86_virt_spec_ctrl(u64 guest_spec_ctrl, u64 guest_virt_spec_ctrl, bool setguest) { - u64 msrval, guestval = guest_spec_ctrl, hostval = spec_ctrl_current(); + u64 guestval, hostval; struct thread_info *ti = current_thread_info(); - if (static_cpu_has(X86_FEATURE_MSR_SPEC_CTRL)) { - if (hostval != guestval) { - msrval = setguest ? guestval : hostval; - wrmsrl(MSR_IA32_SPEC_CTRL, msrval); - } - } - /* * If SSBD is not handled in MSR_SPEC_CTRL on AMD, update * MSR_AMD64_L2_CFG or MSR_VIRT_SPEC_CTRL if supported. diff --git a/arch/x86/kvm/kvm-asm-offsets.c b/arch/x86/kvm/kvm-asm-offsets.c index 1b805cd24d66..24a710d37323 100644 --- a/arch/x86/kvm/kvm-asm-offsets.c +++ b/arch/x86/kvm/kvm-asm-offsets.c @@ -16,6 +16,7 @@ static void __used common(void) BLANK(); OFFSET(SVM_vcpu_arch_regs, vcpu_svm, vcpu.arch.regs); OFFSET(SVM_current_vmcb, vcpu_svm, current_vmcb); + OFFSET(SVM_spec_ctrl, vcpu_svm, spec_ctrl); OFFSET(SVM_vmcb01, vcpu_svm, vmcb01); OFFSET(KVM_VMCB_pa, kvm_vmcb_info, pa); OFFSET(SD_save_area_pa, svm_cpu_data, save_area_pa); diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 469c1b5617af..cf1aed25f4ab 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -720,6 +720,15 @@ static bool msr_write_intercepted(struct kvm_vcpu *vcpu, u32 msr) u32 offset; u32 *msrpm; + /* + * For non-nested case: + * If the L01 MSR bitmap does not intercept the MSR, then we need to + * save it. + * + * For nested case: + * If the L02 MSR bitmap does not intercept the MSR, then we need to + * save it. + */ msrpm = is_guest_mode(vcpu) ? to_svm(vcpu)->nested.msrpm: to_svm(vcpu)->msrpm; @@ -3901,16 +3910,16 @@ static fastpath_t svm_exit_handlers_fastpath(struct kvm_vcpu *vcpu) return EXIT_FASTPATH_NONE; } -static noinstr void svm_vcpu_enter_exit(struct kvm_vcpu *vcpu) +static noinstr void svm_vcpu_enter_exit(struct kvm_vcpu *vcpu, bool spec_ctrl_intercepted) { struct vcpu_svm *svm = to_svm(vcpu); guest_state_enter_irqoff(); if (sev_es_guest(vcpu->kvm)) - __svm_sev_es_vcpu_run(svm); + __svm_sev_es_vcpu_run(svm, spec_ctrl_intercepted); else - __svm_vcpu_run(svm); + __svm_vcpu_run(svm, spec_ctrl_intercepted); guest_state_exit_irqoff(); } @@ -3918,6 +3927,7 @@ static noinstr void svm_vcpu_enter_exit(struct kvm_vcpu *vcpu) static __no_kcsan fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu) { struct vcpu_svm *svm = to_svm(vcpu); + bool spec_ctrl_intercepted = msr_write_intercepted(vcpu, MSR_IA32_SPEC_CTRL); trace_kvm_entry(vcpu); @@ -3976,26 +3986,7 @@ static __no_kcsan fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu) if (!static_cpu_has(X86_FEATURE_V_SPEC_CTRL)) x86_spec_ctrl_set_guest(svm->spec_ctrl, svm->virt_spec_ctrl); - svm_vcpu_enter_exit(vcpu); - - /* - * We do not use IBRS in the kernel. If this vCPU has used the - * SPEC_CTRL MSR it may have left it on; save the value and - * turn it off. This is much more efficient than blindly adding - * it to the atomic save/restore list. Especially as the former - * (Saving guest MSRs on vmexit) doesn't even exist in KVM. - * - * For non-nested case: - * If the L01 MSR bitmap does not intercept the MSR, then we need to - * save it. - * - * For nested case: - * If the L02 MSR bitmap does not intercept the MSR, then we need to - * save it. - */ - if (!static_cpu_has(X86_FEATURE_V_SPEC_CTRL) && - unlikely(!msr_write_intercepted(vcpu, MSR_IA32_SPEC_CTRL))) - svm->spec_ctrl = native_read_msr(MSR_IA32_SPEC_CTRL); + svm_vcpu_enter_exit(vcpu, spec_ctrl_intercepted); if (!sev_es_guest(vcpu->kvm)) reload_tss(vcpu); diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index 83955a4e520e..199a2ecef1ce 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -682,7 +682,7 @@ void sev_es_unmap_ghcb(struct vcpu_svm *svm); /* vmenter.S */ -void __svm_sev_es_vcpu_run(struct vcpu_svm *svm); -void __svm_vcpu_run(struct vcpu_svm *svm); +void __svm_sev_es_vcpu_run(struct vcpu_svm *svm, bool spec_ctrl_intercepted); +void __svm_vcpu_run(struct vcpu_svm *svm, bool spec_ctrl_intercepted); #endif diff --git a/arch/x86/kvm/svm/vmenter.S b/arch/x86/kvm/svm/vmenter.S index 57440acfc73e..34367dc203f2 100644 --- a/arch/x86/kvm/svm/vmenter.S +++ b/arch/x86/kvm/svm/vmenter.S @@ -32,9 +32,69 @@ .section .noinstr.text, "ax" +.macro RESTORE_GUEST_SPEC_CTRL + /* No need to do anything if SPEC_CTRL is unset or V_SPEC_CTRL is set */ + ALTERNATIVE_2 "", \ + "jmp 800f", X86_FEATURE_MSR_SPEC_CTRL, \ + "", X86_FEATURE_V_SPEC_CTRL +801: +.endm +.macro RESTORE_GUEST_SPEC_CTRL_BODY +800: + /* + * SPEC_CTRL handling: if the guest's SPEC_CTRL value differs from the + * host's, write the MSR. This is kept out-of-line so that the common + * case does not have to jump. + * + * IMPORTANT: To avoid RSB underflow attacks and any other nastiness, + * there must not be any returns or indirect branches between this code + * and vmentry. + */ + movl SVM_spec_ctrl(%_ASM_DI), %eax + cmp PER_CPU_VAR(x86_spec_ctrl_current), %eax + je 801b + mov $MSR_IA32_SPEC_CTRL, %ecx + xor %edx, %edx + wrmsr + jmp 801b +.endm + +.macro RESTORE_HOST_SPEC_CTRL + /* No need to do anything if SPEC_CTRL is unset or V_SPEC_CTRL is set */ + ALTERNATIVE_2 "", \ + "jmp 900f", X86_FEATURE_MSR_SPEC_CTRL, \ + "", X86_FEATURE_V_SPEC_CTRL +901: +.endm +.macro RESTORE_HOST_SPEC_CTRL_BODY +900: + /* Same for after vmexit. */ + mov $MSR_IA32_SPEC_CTRL, %ecx + + /* + * Load the value that the guest had written into MSR_IA32_SPEC_CTRL, + * if it was not intercepted during guest execution. + */ + cmpb $0, (%_ASM_SP) + jnz 998f + rdmsr + movl %eax, SVM_spec_ctrl(%_ASM_DI) +998: + + /* Now restore the host value of the MSR if different from the guest's. */ + movl PER_CPU_VAR(x86_spec_ctrl_current), %eax + cmp SVM_spec_ctrl(%_ASM_DI), %eax + je 901b + xor %edx, %edx + wrmsr + jmp 901b +.endm + + /** * __svm_vcpu_run - Run a vCPU via a transition to SVM guest mode * @svm: struct vcpu_svm * + * @spec_ctrl_intercepted: bool */ SYM_FUNC_START(__svm_vcpu_run) push %_ASM_BP @@ -54,17 +114,26 @@ SYM_FUNC_START(__svm_vcpu_run) * order compared to when they are needed. */ + /* Accessed directly from the stack in RESTORE_HOST_SPEC_CTRL. */ + push %_ASM_ARG2 + /* Needed to restore access to percpu variables. */ __ASM_SIZE(push) PER_CPU_VAR(svm_data + SD_save_area_pa) - /* Save @svm. */ + /* Finally save @svm. */ push %_ASM_ARG1 .ifnc _ASM_ARG1, _ASM_DI - /* Move @svm to RDI. */ + /* + * Stash @svm in RDI early. On 32-bit, arguments are in RAX, RCX + * and RDX which are clobbered by RESTORE_GUEST_SPEC_CTRL. + */ mov %_ASM_ARG1, %_ASM_DI .endif + /* Clobbers RAX, RCX, RDX. */ + RESTORE_GUEST_SPEC_CTRL + /* * Use a single vmcb (vmcb01 because it's always valid) for * context switching guest state via VMLOAD/VMSAVE, that way @@ -142,6 +211,9 @@ SYM_FUNC_START(__svm_vcpu_run) FILL_RETURN_BUFFER %_ASM_AX, RSB_CLEAR_LOOPS, X86_FEATURE_RETPOLINE #endif + /* Clobbers RAX, RCX, RDX. */ + RESTORE_HOST_SPEC_CTRL + /* * Mitigate RETBleed for AMD/Hygon Zen uarch. RET should be * untrained as soon as we exit the VM and are back to the @@ -177,6 +249,9 @@ SYM_FUNC_START(__svm_vcpu_run) xor %r15d, %r15d #endif + /* "Pop" @spec_ctrl_intercepted. */ + pop %_ASM_BX + pop %_ASM_BX #ifdef CONFIG_X86_64 @@ -191,6 +266,9 @@ SYM_FUNC_START(__svm_vcpu_run) pop %_ASM_BP RET + RESTORE_GUEST_SPEC_CTRL_BODY + RESTORE_HOST_SPEC_CTRL_BODY + 10: cmpb $0, kvm_rebooting jne 2b ud2 @@ -214,6 +292,7 @@ SYM_FUNC_END(__svm_vcpu_run) /** * __svm_sev_es_vcpu_run - Run a SEV-ES vCPU via a transition to SVM guest mode * @svm: struct vcpu_svm * + * @spec_ctrl_intercepted: bool */ SYM_FUNC_START(__svm_sev_es_vcpu_run) push %_ASM_BP @@ -228,8 +307,30 @@ SYM_FUNC_START(__svm_sev_es_vcpu_run) #endif push %_ASM_BX + /* + * Save variables needed after vmexit on the stack, in inverse + * order compared to when they are needed. + */ + + /* Accessed directly from the stack in RESTORE_HOST_SPEC_CTRL. */ + push %_ASM_ARG2 + + /* Save @svm. */ + push %_ASM_ARG1 + +.ifnc _ASM_ARG1, _ASM_DI + /* + * Stash @svm in RDI early. On 32-bit, arguments are in RAX, RCX + * and RDX which are clobbered by RESTORE_GUEST_SPEC_CTRL. + */ + mov %_ASM_ARG1, %_ASM_DI +.endif + + /* Clobbers RAX, RCX, RDX. */ + RESTORE_GUEST_SPEC_CTRL + /* Get svm->current_vmcb->pa into RAX. */ - mov SVM_current_vmcb(%_ASM_ARG1), %_ASM_AX + mov SVM_current_vmcb(%_ASM_DI), %_ASM_AX mov KVM_VMCB_pa(%_ASM_AX), %_ASM_AX /* Enter guest mode */ @@ -239,11 +340,17 @@ SYM_FUNC_START(__svm_sev_es_vcpu_run) 2: cli + /* Pop @svm to RDI, guest registers have been saved already. */ + pop %_ASM_DI + #ifdef CONFIG_RETPOLINE /* IMPORTANT: Stuff the RSB immediately after VM-Exit, before RET! */ FILL_RETURN_BUFFER %_ASM_AX, RSB_CLEAR_LOOPS, X86_FEATURE_RETPOLINE #endif + /* Clobbers RAX, RCX, RDX. */ + RESTORE_HOST_SPEC_CTRL + /* * Mitigate RETBleed for AMD/Hygon Zen uarch. RET should be * untrained as soon as we exit the VM and are back to the @@ -253,6 +360,9 @@ SYM_FUNC_START(__svm_sev_es_vcpu_run) */ UNTRAIN_RET + /* "Pop" @spec_ctrl_intercepted. */ + pop %_ASM_BX + pop %_ASM_BX #ifdef CONFIG_X86_64 @@ -267,6 +377,9 @@ SYM_FUNC_START(__svm_sev_es_vcpu_run) pop %_ASM_BP RET + RESTORE_GUEST_SPEC_CTRL_BODY + RESTORE_HOST_SPEC_CTRL_BODY + 3: cmpb $0, kvm_rebooting jne 2b ud2

2 years, 1 month

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FAILED: patch "[PATCH] KVM: SVM: move MSR_IA32_SPEC_CTRL save/restore to assembly" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. Possible dependencies: 9f2febf3f04d ("KVM: SVM: move MSR_IA32_SPEC_CTRL save/restore to assembly") e287bd005ad9 ("KVM: SVM: restore host save area from assembly") e61ab42de874 ("KVM: SVM: move guest vmsave/vmload back to assembly") 73412dfeea72 ("KVM: SVM: do not allocate struct svm_cpu_data dynamically") 181d0fb0bb02 ("KVM: SVM: remove dead field from struct svm_cpu_data") f6d58266d731 ("KVM: SVM: retrieve VMCB from assembly") f7ef280132f9 ("KVM: SVM: adjust register allocation for __svm_vcpu_run()") 16fdc1de169e ("KVM: SVM: replace regs argument of __svm_vcpu_run() with vcpu_svm") debc5a1ec0d1 ("KVM: x86: use a separate asm-offsets.c file") 07853adc29a0 ("KVM: VMX: Prevent RSB underflow before vmenter") fc02735b14ff ("KVM: VMX: Prevent guest RSB poisoning attacks with eIBRS") bb06650634d3 ("KVM: VMX: Convert launched argument to flags") 8bd200d23ec4 ("KVM: VMX: Flatten __vmx_vcpu_run()") acac5e98ef8d ("x86/speculation: Remove x86_spec_ctrl_mask") bbb69e8bee1b ("x86/speculation: Use cached host SPEC_CTRL value for guest entry/exit") 7c693f54c873 ("x86/speculation: Add spectre_v2=ibrs option to support Kernel IBRS") c779bc1a9002 ("x86/bugs: Optimize SPEC_CTRL MSR writes") caa0ff24d5d0 ("x86/bugs: Keep a per-CPU IA32_SPEC_CTRL value") a149180fbcf3 ("x86: Add magic AMD return-thunk") d9e9d2300681 ("x86,objtool: Create .return_sites") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 9f2febf3f04daebdaaa5a43cfa20e3844905c0f9 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini <pbonzini(a)redhat.com> Date: Fri, 30 Sep 2022 14:24:40 -0400 Subject: [PATCH] KVM: SVM: move MSR_IA32_SPEC_CTRL save/restore to assembly Restoration of the host IA32_SPEC_CTRL value is probably too late with respect to the return thunk training sequence. With respect to the user/kernel boundary, AMD says, "If software chooses to toggle STIBP (e.g., set STIBP on kernel entry, and clear it on kernel exit), software should set STIBP to 1 before executing the return thunk training sequence." I assume the same requirements apply to the guest/host boundary. The return thunk training sequence is in vmenter.S, quite close to the VM-exit. On hosts without V_SPEC_CTRL, however, the host's IA32_SPEC_CTRL value is not restored until much later. To avoid this, move the restoration of host SPEC_CTRL to assembly and, for consistency, move the restoration of the guest SPEC_CTRL as well. This is not particularly difficult, apart from some care to cover both 32- and 64-bit, and to share code between SEV-ES and normal vmentry. Cc: stable(a)vger.kernel.org Fixes: a149180fbcf3 ("x86: Add magic AMD return-thunk") Suggested-by: Jim Mattson <jmattson(a)google.com> Reviewed-by: Sean Christopherson <seanjc(a)google.com> Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index da7c361f47e0..6ec0b7ce7453 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -196,22 +196,15 @@ void __init check_bugs(void) } /* - * NOTE: This function is *only* called for SVM. VMX spec_ctrl handling is - * done in vmenter.S. + * NOTE: This function is *only* called for SVM, since Intel uses + * MSR_IA32_SPEC_CTRL for SSBD. */ void x86_virt_spec_ctrl(u64 guest_spec_ctrl, u64 guest_virt_spec_ctrl, bool setguest) { - u64 msrval, guestval = guest_spec_ctrl, hostval = spec_ctrl_current(); + u64 guestval, hostval; struct thread_info *ti = current_thread_info(); - if (static_cpu_has(X86_FEATURE_MSR_SPEC_CTRL)) { - if (hostval != guestval) { - msrval = setguest ? guestval : hostval; - wrmsrl(MSR_IA32_SPEC_CTRL, msrval); - } - } - /* * If SSBD is not handled in MSR_SPEC_CTRL on AMD, update * MSR_AMD64_L2_CFG or MSR_VIRT_SPEC_CTRL if supported. diff --git a/arch/x86/kvm/kvm-asm-offsets.c b/arch/x86/kvm/kvm-asm-offsets.c index 1b805cd24d66..24a710d37323 100644 --- a/arch/x86/kvm/kvm-asm-offsets.c +++ b/arch/x86/kvm/kvm-asm-offsets.c @@ -16,6 +16,7 @@ static void __used common(void) BLANK(); OFFSET(SVM_vcpu_arch_regs, vcpu_svm, vcpu.arch.regs); OFFSET(SVM_current_vmcb, vcpu_svm, current_vmcb); + OFFSET(SVM_spec_ctrl, vcpu_svm, spec_ctrl); OFFSET(SVM_vmcb01, vcpu_svm, vmcb01); OFFSET(KVM_VMCB_pa, kvm_vmcb_info, pa); OFFSET(SD_save_area_pa, svm_cpu_data, save_area_pa); diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 469c1b5617af..cf1aed25f4ab 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -720,6 +720,15 @@ static bool msr_write_intercepted(struct kvm_vcpu *vcpu, u32 msr) u32 offset; u32 *msrpm; + /* + * For non-nested case: + * If the L01 MSR bitmap does not intercept the MSR, then we need to + * save it. + * + * For nested case: + * If the L02 MSR bitmap does not intercept the MSR, then we need to + * save it. + */ msrpm = is_guest_mode(vcpu) ? to_svm(vcpu)->nested.msrpm: to_svm(vcpu)->msrpm; @@ -3901,16 +3910,16 @@ static fastpath_t svm_exit_handlers_fastpath(struct kvm_vcpu *vcpu) return EXIT_FASTPATH_NONE; } -static noinstr void svm_vcpu_enter_exit(struct kvm_vcpu *vcpu) +static noinstr void svm_vcpu_enter_exit(struct kvm_vcpu *vcpu, bool spec_ctrl_intercepted) { struct vcpu_svm *svm = to_svm(vcpu); guest_state_enter_irqoff(); if (sev_es_guest(vcpu->kvm)) - __svm_sev_es_vcpu_run(svm); + __svm_sev_es_vcpu_run(svm, spec_ctrl_intercepted); else - __svm_vcpu_run(svm); + __svm_vcpu_run(svm, spec_ctrl_intercepted); guest_state_exit_irqoff(); } @@ -3918,6 +3927,7 @@ static noinstr void svm_vcpu_enter_exit(struct kvm_vcpu *vcpu) static __no_kcsan fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu) { struct vcpu_svm *svm = to_svm(vcpu); + bool spec_ctrl_intercepted = msr_write_intercepted(vcpu, MSR_IA32_SPEC_CTRL); trace_kvm_entry(vcpu); @@ -3976,26 +3986,7 @@ static __no_kcsan fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu) if (!static_cpu_has(X86_FEATURE_V_SPEC_CTRL)) x86_spec_ctrl_set_guest(svm->spec_ctrl, svm->virt_spec_ctrl); - svm_vcpu_enter_exit(vcpu); - - /* - * We do not use IBRS in the kernel. If this vCPU has used the - * SPEC_CTRL MSR it may have left it on; save the value and - * turn it off. This is much more efficient than blindly adding - * it to the atomic save/restore list. Especially as the former - * (Saving guest MSRs on vmexit) doesn't even exist in KVM. - * - * For non-nested case: - * If the L01 MSR bitmap does not intercept the MSR, then we need to - * save it. - * - * For nested case: - * If the L02 MSR bitmap does not intercept the MSR, then we need to - * save it. - */ - if (!static_cpu_has(X86_FEATURE_V_SPEC_CTRL) && - unlikely(!msr_write_intercepted(vcpu, MSR_IA32_SPEC_CTRL))) - svm->spec_ctrl = native_read_msr(MSR_IA32_SPEC_CTRL); + svm_vcpu_enter_exit(vcpu, spec_ctrl_intercepted); if (!sev_es_guest(vcpu->kvm)) reload_tss(vcpu); diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index 83955a4e520e..199a2ecef1ce 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -682,7 +682,7 @@ void sev_es_unmap_ghcb(struct vcpu_svm *svm); /* vmenter.S */ -void __svm_sev_es_vcpu_run(struct vcpu_svm *svm); -void __svm_vcpu_run(struct vcpu_svm *svm); +void __svm_sev_es_vcpu_run(struct vcpu_svm *svm, bool spec_ctrl_intercepted); +void __svm_vcpu_run(struct vcpu_svm *svm, bool spec_ctrl_intercepted); #endif diff --git a/arch/x86/kvm/svm/vmenter.S b/arch/x86/kvm/svm/vmenter.S index 57440acfc73e..34367dc203f2 100644 --- a/arch/x86/kvm/svm/vmenter.S +++ b/arch/x86/kvm/svm/vmenter.S @@ -32,9 +32,69 @@ .section .noinstr.text, "ax" +.macro RESTORE_GUEST_SPEC_CTRL + /* No need to do anything if SPEC_CTRL is unset or V_SPEC_CTRL is set */ + ALTERNATIVE_2 "", \ + "jmp 800f", X86_FEATURE_MSR_SPEC_CTRL, \ + "", X86_FEATURE_V_SPEC_CTRL +801: +.endm +.macro RESTORE_GUEST_SPEC_CTRL_BODY +800: + /* + * SPEC_CTRL handling: if the guest's SPEC_CTRL value differs from the + * host's, write the MSR. This is kept out-of-line so that the common + * case does not have to jump. + * + * IMPORTANT: To avoid RSB underflow attacks and any other nastiness, + * there must not be any returns or indirect branches between this code + * and vmentry. + */ + movl SVM_spec_ctrl(%_ASM_DI), %eax + cmp PER_CPU_VAR(x86_spec_ctrl_current), %eax + je 801b + mov $MSR_IA32_SPEC_CTRL, %ecx + xor %edx, %edx + wrmsr + jmp 801b +.endm + +.macro RESTORE_HOST_SPEC_CTRL + /* No need to do anything if SPEC_CTRL is unset or V_SPEC_CTRL is set */ + ALTERNATIVE_2 "", \ + "jmp 900f", X86_FEATURE_MSR_SPEC_CTRL, \ + "", X86_FEATURE_V_SPEC_CTRL +901: +.endm +.macro RESTORE_HOST_SPEC_CTRL_BODY +900: + /* Same for after vmexit. */ + mov $MSR_IA32_SPEC_CTRL, %ecx + + /* + * Load the value that the guest had written into MSR_IA32_SPEC_CTRL, + * if it was not intercepted during guest execution. + */ + cmpb $0, (%_ASM_SP) + jnz 998f + rdmsr + movl %eax, SVM_spec_ctrl(%_ASM_DI) +998: + + /* Now restore the host value of the MSR if different from the guest's. */ + movl PER_CPU_VAR(x86_spec_ctrl_current), %eax + cmp SVM_spec_ctrl(%_ASM_DI), %eax + je 901b + xor %edx, %edx + wrmsr + jmp 901b +.endm + + /** * __svm_vcpu_run - Run a vCPU via a transition to SVM guest mode * @svm: struct vcpu_svm * + * @spec_ctrl_intercepted: bool */ SYM_FUNC_START(__svm_vcpu_run) push %_ASM_BP @@ -54,17 +114,26 @@ SYM_FUNC_START(__svm_vcpu_run) * order compared to when they are needed. */ + /* Accessed directly from the stack in RESTORE_HOST_SPEC_CTRL. */ + push %_ASM_ARG2 + /* Needed to restore access to percpu variables. */ __ASM_SIZE(push) PER_CPU_VAR(svm_data + SD_save_area_pa) - /* Save @svm. */ + /* Finally save @svm. */ push %_ASM_ARG1 .ifnc _ASM_ARG1, _ASM_DI - /* Move @svm to RDI. */ + /* + * Stash @svm in RDI early. On 32-bit, arguments are in RAX, RCX + * and RDX which are clobbered by RESTORE_GUEST_SPEC_CTRL. + */ mov %_ASM_ARG1, %_ASM_DI .endif + /* Clobbers RAX, RCX, RDX. */ + RESTORE_GUEST_SPEC_CTRL + /* * Use a single vmcb (vmcb01 because it's always valid) for * context switching guest state via VMLOAD/VMSAVE, that way @@ -142,6 +211,9 @@ SYM_FUNC_START(__svm_vcpu_run) FILL_RETURN_BUFFER %_ASM_AX, RSB_CLEAR_LOOPS, X86_FEATURE_RETPOLINE #endif + /* Clobbers RAX, RCX, RDX. */ + RESTORE_HOST_SPEC_CTRL + /* * Mitigate RETBleed for AMD/Hygon Zen uarch. RET should be * untrained as soon as we exit the VM and are back to the @@ -177,6 +249,9 @@ SYM_FUNC_START(__svm_vcpu_run) xor %r15d, %r15d #endif + /* "Pop" @spec_ctrl_intercepted. */ + pop %_ASM_BX + pop %_ASM_BX #ifdef CONFIG_X86_64 @@ -191,6 +266,9 @@ SYM_FUNC_START(__svm_vcpu_run) pop %_ASM_BP RET + RESTORE_GUEST_SPEC_CTRL_BODY + RESTORE_HOST_SPEC_CTRL_BODY + 10: cmpb $0, kvm_rebooting jne 2b ud2 @@ -214,6 +292,7 @@ SYM_FUNC_END(__svm_vcpu_run) /** * __svm_sev_es_vcpu_run - Run a SEV-ES vCPU via a transition to SVM guest mode * @svm: struct vcpu_svm * + * @spec_ctrl_intercepted: bool */ SYM_FUNC_START(__svm_sev_es_vcpu_run) push %_ASM_BP @@ -228,8 +307,30 @@ SYM_FUNC_START(__svm_sev_es_vcpu_run) #endif push %_ASM_BX + /* + * Save variables needed after vmexit on the stack, in inverse + * order compared to when they are needed. + */ + + /* Accessed directly from the stack in RESTORE_HOST_SPEC_CTRL. */ + push %_ASM_ARG2 + + /* Save @svm. */ + push %_ASM_ARG1 + +.ifnc _ASM_ARG1, _ASM_DI + /* + * Stash @svm in RDI early. On 32-bit, arguments are in RAX, RCX + * and RDX which are clobbered by RESTORE_GUEST_SPEC_CTRL. + */ + mov %_ASM_ARG1, %_ASM_DI +.endif + + /* Clobbers RAX, RCX, RDX. */ + RESTORE_GUEST_SPEC_CTRL + /* Get svm->current_vmcb->pa into RAX. */ - mov SVM_current_vmcb(%_ASM_ARG1), %_ASM_AX + mov SVM_current_vmcb(%_ASM_DI), %_ASM_AX mov KVM_VMCB_pa(%_ASM_AX), %_ASM_AX /* Enter guest mode */ @@ -239,11 +340,17 @@ SYM_FUNC_START(__svm_sev_es_vcpu_run) 2: cli + /* Pop @svm to RDI, guest registers have been saved already. */ + pop %_ASM_DI + #ifdef CONFIG_RETPOLINE /* IMPORTANT: Stuff the RSB immediately after VM-Exit, before RET! */ FILL_RETURN_BUFFER %_ASM_AX, RSB_CLEAR_LOOPS, X86_FEATURE_RETPOLINE #endif + /* Clobbers RAX, RCX, RDX. */ + RESTORE_HOST_SPEC_CTRL + /* * Mitigate RETBleed for AMD/Hygon Zen uarch. RET should be * untrained as soon as we exit the VM and are back to the @@ -253,6 +360,9 @@ SYM_FUNC_START(__svm_sev_es_vcpu_run) */ UNTRAIN_RET + /* "Pop" @spec_ctrl_intercepted. */ + pop %_ASM_BX + pop %_ASM_BX #ifdef CONFIG_X86_64 @@ -267,6 +377,9 @@ SYM_FUNC_START(__svm_sev_es_vcpu_run) pop %_ASM_BP RET + RESTORE_GUEST_SPEC_CTRL_BODY + RESTORE_HOST_SPEC_CTRL_BODY + 3: cmpb $0, kvm_rebooting jne 2b ud2

2 years, 1 month

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FAILED: patch "[PATCH] KVM: SVM: move MSR_IA32_SPEC_CTRL save/restore to assembly" failed to apply to 6.0-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.0-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. Possible dependencies: 9f2febf3f04d ("KVM: SVM: move MSR_IA32_SPEC_CTRL save/restore to assembly") e287bd005ad9 ("KVM: SVM: restore host save area from assembly") e61ab42de874 ("KVM: SVM: move guest vmsave/vmload back to assembly") 73412dfeea72 ("KVM: SVM: do not allocate struct svm_cpu_data dynamically") 181d0fb0bb02 ("KVM: SVM: remove dead field from struct svm_cpu_data") f6d58266d731 ("KVM: SVM: retrieve VMCB from assembly") f7ef280132f9 ("KVM: SVM: adjust register allocation for __svm_vcpu_run()") 16fdc1de169e ("KVM: SVM: replace regs argument of __svm_vcpu_run() with vcpu_svm") debc5a1ec0d1 ("KVM: x86: use a separate asm-offsets.c file") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 9f2febf3f04daebdaaa5a43cfa20e3844905c0f9 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini <pbonzini(a)redhat.com> Date: Fri, 30 Sep 2022 14:24:40 -0400 Subject: [PATCH] KVM: SVM: move MSR_IA32_SPEC_CTRL save/restore to assembly Restoration of the host IA32_SPEC_CTRL value is probably too late with respect to the return thunk training sequence. With respect to the user/kernel boundary, AMD says, "If software chooses to toggle STIBP (e.g., set STIBP on kernel entry, and clear it on kernel exit), software should set STIBP to 1 before executing the return thunk training sequence." I assume the same requirements apply to the guest/host boundary. The return thunk training sequence is in vmenter.S, quite close to the VM-exit. On hosts without V_SPEC_CTRL, however, the host's IA32_SPEC_CTRL value is not restored until much later. To avoid this, move the restoration of host SPEC_CTRL to assembly and, for consistency, move the restoration of the guest SPEC_CTRL as well. This is not particularly difficult, apart from some care to cover both 32- and 64-bit, and to share code between SEV-ES and normal vmentry. Cc: stable(a)vger.kernel.org Fixes: a149180fbcf3 ("x86: Add magic AMD return-thunk") Suggested-by: Jim Mattson <jmattson(a)google.com> Reviewed-by: Sean Christopherson <seanjc(a)google.com> Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index da7c361f47e0..6ec0b7ce7453 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -196,22 +196,15 @@ void __init check_bugs(void) } /* - * NOTE: This function is *only* called for SVM. VMX spec_ctrl handling is - * done in vmenter.S. + * NOTE: This function is *only* called for SVM, since Intel uses + * MSR_IA32_SPEC_CTRL for SSBD. */ void x86_virt_spec_ctrl(u64 guest_spec_ctrl, u64 guest_virt_spec_ctrl, bool setguest) { - u64 msrval, guestval = guest_spec_ctrl, hostval = spec_ctrl_current(); + u64 guestval, hostval; struct thread_info *ti = current_thread_info(); - if (static_cpu_has(X86_FEATURE_MSR_SPEC_CTRL)) { - if (hostval != guestval) { - msrval = setguest ? guestval : hostval; - wrmsrl(MSR_IA32_SPEC_CTRL, msrval); - } - } - /* * If SSBD is not handled in MSR_SPEC_CTRL on AMD, update * MSR_AMD64_L2_CFG or MSR_VIRT_SPEC_CTRL if supported. diff --git a/arch/x86/kvm/kvm-asm-offsets.c b/arch/x86/kvm/kvm-asm-offsets.c index 1b805cd24d66..24a710d37323 100644 --- a/arch/x86/kvm/kvm-asm-offsets.c +++ b/arch/x86/kvm/kvm-asm-offsets.c @@ -16,6 +16,7 @@ static void __used common(void) BLANK(); OFFSET(SVM_vcpu_arch_regs, vcpu_svm, vcpu.arch.regs); OFFSET(SVM_current_vmcb, vcpu_svm, current_vmcb); + OFFSET(SVM_spec_ctrl, vcpu_svm, spec_ctrl); OFFSET(SVM_vmcb01, vcpu_svm, vmcb01); OFFSET(KVM_VMCB_pa, kvm_vmcb_info, pa); OFFSET(SD_save_area_pa, svm_cpu_data, save_area_pa); diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 469c1b5617af..cf1aed25f4ab 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -720,6 +720,15 @@ static bool msr_write_intercepted(struct kvm_vcpu *vcpu, u32 msr) u32 offset; u32 *msrpm; + /* + * For non-nested case: + * If the L01 MSR bitmap does not intercept the MSR, then we need to + * save it. + * + * For nested case: + * If the L02 MSR bitmap does not intercept the MSR, then we need to + * save it. + */ msrpm = is_guest_mode(vcpu) ? to_svm(vcpu)->nested.msrpm: to_svm(vcpu)->msrpm; @@ -3901,16 +3910,16 @@ static fastpath_t svm_exit_handlers_fastpath(struct kvm_vcpu *vcpu) return EXIT_FASTPATH_NONE; } -static noinstr void svm_vcpu_enter_exit(struct kvm_vcpu *vcpu) +static noinstr void svm_vcpu_enter_exit(struct kvm_vcpu *vcpu, bool spec_ctrl_intercepted) { struct vcpu_svm *svm = to_svm(vcpu); guest_state_enter_irqoff(); if (sev_es_guest(vcpu->kvm)) - __svm_sev_es_vcpu_run(svm); + __svm_sev_es_vcpu_run(svm, spec_ctrl_intercepted); else - __svm_vcpu_run(svm); + __svm_vcpu_run(svm, spec_ctrl_intercepted); guest_state_exit_irqoff(); } @@ -3918,6 +3927,7 @@ static noinstr void svm_vcpu_enter_exit(struct kvm_vcpu *vcpu) static __no_kcsan fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu) { struct vcpu_svm *svm = to_svm(vcpu); + bool spec_ctrl_intercepted = msr_write_intercepted(vcpu, MSR_IA32_SPEC_CTRL); trace_kvm_entry(vcpu); @@ -3976,26 +3986,7 @@ static __no_kcsan fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu) if (!static_cpu_has(X86_FEATURE_V_SPEC_CTRL)) x86_spec_ctrl_set_guest(svm->spec_ctrl, svm->virt_spec_ctrl); - svm_vcpu_enter_exit(vcpu); - - /* - * We do not use IBRS in the kernel. If this vCPU has used the - * SPEC_CTRL MSR it may have left it on; save the value and - * turn it off. This is much more efficient than blindly adding - * it to the atomic save/restore list. Especially as the former - * (Saving guest MSRs on vmexit) doesn't even exist in KVM. - * - * For non-nested case: - * If the L01 MSR bitmap does not intercept the MSR, then we need to - * save it. - * - * For nested case: - * If the L02 MSR bitmap does not intercept the MSR, then we need to - * save it. - */ - if (!static_cpu_has(X86_FEATURE_V_SPEC_CTRL) && - unlikely(!msr_write_intercepted(vcpu, MSR_IA32_SPEC_CTRL))) - svm->spec_ctrl = native_read_msr(MSR_IA32_SPEC_CTRL); + svm_vcpu_enter_exit(vcpu, spec_ctrl_intercepted); if (!sev_es_guest(vcpu->kvm)) reload_tss(vcpu); diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index 83955a4e520e..199a2ecef1ce 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -682,7 +682,7 @@ void sev_es_unmap_ghcb(struct vcpu_svm *svm); /* vmenter.S */ -void __svm_sev_es_vcpu_run(struct vcpu_svm *svm); -void __svm_vcpu_run(struct vcpu_svm *svm); +void __svm_sev_es_vcpu_run(struct vcpu_svm *svm, bool spec_ctrl_intercepted); +void __svm_vcpu_run(struct vcpu_svm *svm, bool spec_ctrl_intercepted); #endif diff --git a/arch/x86/kvm/svm/vmenter.S b/arch/x86/kvm/svm/vmenter.S index 57440acfc73e..34367dc203f2 100644 --- a/arch/x86/kvm/svm/vmenter.S +++ b/arch/x86/kvm/svm/vmenter.S @@ -32,9 +32,69 @@ .section .noinstr.text, "ax" +.macro RESTORE_GUEST_SPEC_CTRL + /* No need to do anything if SPEC_CTRL is unset or V_SPEC_CTRL is set */ + ALTERNATIVE_2 "", \ + "jmp 800f", X86_FEATURE_MSR_SPEC_CTRL, \ + "", X86_FEATURE_V_SPEC_CTRL +801: +.endm +.macro RESTORE_GUEST_SPEC_CTRL_BODY +800: + /* + * SPEC_CTRL handling: if the guest's SPEC_CTRL value differs from the + * host's, write the MSR. This is kept out-of-line so that the common + * case does not have to jump. + * + * IMPORTANT: To avoid RSB underflow attacks and any other nastiness, + * there must not be any returns or indirect branches between this code + * and vmentry. + */ + movl SVM_spec_ctrl(%_ASM_DI), %eax + cmp PER_CPU_VAR(x86_spec_ctrl_current), %eax + je 801b + mov $MSR_IA32_SPEC_CTRL, %ecx + xor %edx, %edx + wrmsr + jmp 801b +.endm + +.macro RESTORE_HOST_SPEC_CTRL + /* No need to do anything if SPEC_CTRL is unset or V_SPEC_CTRL is set */ + ALTERNATIVE_2 "", \ + "jmp 900f", X86_FEATURE_MSR_SPEC_CTRL, \ + "", X86_FEATURE_V_SPEC_CTRL +901: +.endm +.macro RESTORE_HOST_SPEC_CTRL_BODY +900: + /* Same for after vmexit. */ + mov $MSR_IA32_SPEC_CTRL, %ecx + + /* + * Load the value that the guest had written into MSR_IA32_SPEC_CTRL, + * if it was not intercepted during guest execution. + */ + cmpb $0, (%_ASM_SP) + jnz 998f + rdmsr + movl %eax, SVM_spec_ctrl(%_ASM_DI) +998: + + /* Now restore the host value of the MSR if different from the guest's. */ + movl PER_CPU_VAR(x86_spec_ctrl_current), %eax + cmp SVM_spec_ctrl(%_ASM_DI), %eax + je 901b + xor %edx, %edx + wrmsr + jmp 901b +.endm + + /** * __svm_vcpu_run - Run a vCPU via a transition to SVM guest mode * @svm: struct vcpu_svm * + * @spec_ctrl_intercepted: bool */ SYM_FUNC_START(__svm_vcpu_run) push %_ASM_BP @@ -54,17 +114,26 @@ SYM_FUNC_START(__svm_vcpu_run) * order compared to when they are needed. */ + /* Accessed directly from the stack in RESTORE_HOST_SPEC_CTRL. */ + push %_ASM_ARG2 + /* Needed to restore access to percpu variables. */ __ASM_SIZE(push) PER_CPU_VAR(svm_data + SD_save_area_pa) - /* Save @svm. */ + /* Finally save @svm. */ push %_ASM_ARG1 .ifnc _ASM_ARG1, _ASM_DI - /* Move @svm to RDI. */ + /* + * Stash @svm in RDI early. On 32-bit, arguments are in RAX, RCX + * and RDX which are clobbered by RESTORE_GUEST_SPEC_CTRL. + */ mov %_ASM_ARG1, %_ASM_DI .endif + /* Clobbers RAX, RCX, RDX. */ + RESTORE_GUEST_SPEC_CTRL + /* * Use a single vmcb (vmcb01 because it's always valid) for * context switching guest state via VMLOAD/VMSAVE, that way @@ -142,6 +211,9 @@ SYM_FUNC_START(__svm_vcpu_run) FILL_RETURN_BUFFER %_ASM_AX, RSB_CLEAR_LOOPS, X86_FEATURE_RETPOLINE #endif + /* Clobbers RAX, RCX, RDX. */ + RESTORE_HOST_SPEC_CTRL + /* * Mitigate RETBleed for AMD/Hygon Zen uarch. RET should be * untrained as soon as we exit the VM and are back to the @@ -177,6 +249,9 @@ SYM_FUNC_START(__svm_vcpu_run) xor %r15d, %r15d #endif + /* "Pop" @spec_ctrl_intercepted. */ + pop %_ASM_BX + pop %_ASM_BX #ifdef CONFIG_X86_64 @@ -191,6 +266,9 @@ SYM_FUNC_START(__svm_vcpu_run) pop %_ASM_BP RET + RESTORE_GUEST_SPEC_CTRL_BODY + RESTORE_HOST_SPEC_CTRL_BODY + 10: cmpb $0, kvm_rebooting jne 2b ud2 @@ -214,6 +292,7 @@ SYM_FUNC_END(__svm_vcpu_run) /** * __svm_sev_es_vcpu_run - Run a SEV-ES vCPU via a transition to SVM guest mode * @svm: struct vcpu_svm * + * @spec_ctrl_intercepted: bool */ SYM_FUNC_START(__svm_sev_es_vcpu_run) push %_ASM_BP @@ -228,8 +307,30 @@ SYM_FUNC_START(__svm_sev_es_vcpu_run) #endif push %_ASM_BX + /* + * Save variables needed after vmexit on the stack, in inverse + * order compared to when they are needed. + */ + + /* Accessed directly from the stack in RESTORE_HOST_SPEC_CTRL. */ + push %_ASM_ARG2 + + /* Save @svm. */ + push %_ASM_ARG1 + +.ifnc _ASM_ARG1, _ASM_DI + /* + * Stash @svm in RDI early. On 32-bit, arguments are in RAX, RCX + * and RDX which are clobbered by RESTORE_GUEST_SPEC_CTRL. + */ + mov %_ASM_ARG1, %_ASM_DI +.endif + + /* Clobbers RAX, RCX, RDX. */ + RESTORE_GUEST_SPEC_CTRL + /* Get svm->current_vmcb->pa into RAX. */ - mov SVM_current_vmcb(%_ASM_ARG1), %_ASM_AX + mov SVM_current_vmcb(%_ASM_DI), %_ASM_AX mov KVM_VMCB_pa(%_ASM_AX), %_ASM_AX /* Enter guest mode */ @@ -239,11 +340,17 @@ SYM_FUNC_START(__svm_sev_es_vcpu_run) 2: cli + /* Pop @svm to RDI, guest registers have been saved already. */ + pop %_ASM_DI + #ifdef CONFIG_RETPOLINE /* IMPORTANT: Stuff the RSB immediately after VM-Exit, before RET! */ FILL_RETURN_BUFFER %_ASM_AX, RSB_CLEAR_LOOPS, X86_FEATURE_RETPOLINE #endif + /* Clobbers RAX, RCX, RDX. */ + RESTORE_HOST_SPEC_CTRL + /* * Mitigate RETBleed for AMD/Hygon Zen uarch. RET should be * untrained as soon as we exit the VM and are back to the @@ -253,6 +360,9 @@ SYM_FUNC_START(__svm_sev_es_vcpu_run) */ UNTRAIN_RET + /* "Pop" @spec_ctrl_intercepted. */ + pop %_ASM_BX + pop %_ASM_BX #ifdef CONFIG_X86_64 @@ -267,6 +377,9 @@ SYM_FUNC_START(__svm_sev_es_vcpu_run) pop %_ASM_BP RET + RESTORE_GUEST_SPEC_CTRL_BODY + RESTORE_HOST_SPEC_CTRL_BODY + 3: cmpb $0, kvm_rebooting jne 2b ud2

2 years, 1 month

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FAILED: patch "[PATCH] KVM: SVM: replace regs argument of __svm_vcpu_run() with" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. Possible dependencies: 16fdc1de169e ("KVM: SVM: replace regs argument of __svm_vcpu_run() with vcpu_svm") debc5a1ec0d1 ("KVM: x86: use a separate asm-offsets.c file") bb06650634d3 ("KVM: VMX: Convert launched argument to flags") 8bd200d23ec4 ("KVM: VMX: Flatten __vmx_vcpu_run()") 527a534c7326 ("x86/tdx: Provide common base for SEAMCALL and TDCALL C wrappers") 59bd54a84d15 ("x86/tdx: Detect running as a TDX guest in early boot") 6198311093da ("x86/cc: Move arch/x86/{kernel/cc_platform.c => coco/core.c}") f94909ceb1ed ("x86: Prepare asm files for straight-line-speculation") 22da5a07c75e ("x86/lib/atomic64_386_32: Rename things") 1367afaa2ee9 ("x86/entry: Use the correct fence macro after swapgs in kernel CR3") c07e45553da1 ("x86/entry: Add a fence for kernel entry SWAPGS in paranoid_entry()") 6e5772c8d9cf ("Merge tag 'x86_cc_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 16fdc1de169ee0a4e59a8c02244414ec7acd55c3 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini <pbonzini(a)redhat.com> Date: Fri, 30 Sep 2022 14:14:44 -0400 Subject: [PATCH] KVM: SVM: replace regs argument of __svm_vcpu_run() with vcpu_svm Since registers are reachable through vcpu_svm, and we will need to access more fields of that struct, pass it instead of the regs[] array. No functional change intended. Cc: stable(a)vger.kernel.org Fixes: a149180fbcf3 ("x86: Add magic AMD return-thunk") Reviewed-by: Sean Christopherson <seanjc(a)google.com> Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> diff --git a/arch/x86/kvm/Makefile b/arch/x86/kvm/Makefile index a02cf9baacc8..f453a0f96e24 100644 --- a/arch/x86/kvm/Makefile +++ b/arch/x86/kvm/Makefile @@ -35,6 +35,9 @@ obj-$(CONFIG_KVM) += kvm.o obj-$(CONFIG_KVM_INTEL) += kvm-intel.o obj-$(CONFIG_KVM_AMD) += kvm-amd.o +AFLAGS_svm/vmenter.o := -iquote $(obj) +$(obj)/svm/vmenter.o: $(obj)/kvm-asm-offsets.h + AFLAGS_vmx/vmenter.o := -iquote $(obj) $(obj)/vmx/vmenter.o: $(obj)/kvm-asm-offsets.h diff --git a/arch/x86/kvm/kvm-asm-offsets.c b/arch/x86/kvm/kvm-asm-offsets.c index 9d84f2b32d7f..30db96852e2d 100644 --- a/arch/x86/kvm/kvm-asm-offsets.c +++ b/arch/x86/kvm/kvm-asm-offsets.c @@ -8,9 +8,15 @@ #include <linux/kbuild.h> #include "vmx/vmx.h" +#include "svm/svm.h" static void __used common(void) { + if (IS_ENABLED(CONFIG_KVM_AMD)) { + BLANK(); + OFFSET(SVM_vcpu_arch_regs, vcpu_svm, vcpu.arch.regs); + } + if (IS_ENABLED(CONFIG_KVM_INTEL)) { BLANK(); OFFSET(VMX_spec_ctrl, vcpu_vmx, spec_ctrl); diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 58f0077d9357..b412bc5773c5 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -3930,7 +3930,7 @@ static noinstr void svm_vcpu_enter_exit(struct kvm_vcpu *vcpu) * vmcb02 when switching vmcbs for nested virtualization. */ vmload(svm->vmcb01.pa); - __svm_vcpu_run(vmcb_pa, (unsigned long *)&vcpu->arch.regs); + __svm_vcpu_run(vmcb_pa, svm); vmsave(svm->vmcb01.pa); vmload(__sme_page_pa(sd->save_area)); diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index 6a7686bf6900..447e25c9101a 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -684,6 +684,6 @@ void sev_es_unmap_ghcb(struct vcpu_svm *svm); /* vmenter.S */ void __svm_sev_es_vcpu_run(unsigned long vmcb_pa); -void __svm_vcpu_run(unsigned long vmcb_pa, unsigned long *regs); +void __svm_vcpu_run(unsigned long vmcb_pa, struct vcpu_svm *svm); #endif diff --git a/arch/x86/kvm/svm/vmenter.S b/arch/x86/kvm/svm/vmenter.S index 723f8534986c..f0ff41103e4c 100644 --- a/arch/x86/kvm/svm/vmenter.S +++ b/arch/x86/kvm/svm/vmenter.S @@ -4,27 +4,28 @@ #include <asm/bitsperlong.h> #include <asm/kvm_vcpu_regs.h> #include <asm/nospec-branch.h> +#include "kvm-asm-offsets.h" #define WORD_SIZE (BITS_PER_LONG / 8) /* Intentionally omit RAX as it's context switched by hardware */ -#define VCPU_RCX __VCPU_REGS_RCX * WORD_SIZE -#define VCPU_RDX __VCPU_REGS_RDX * WORD_SIZE -#define VCPU_RBX __VCPU_REGS_RBX * WORD_SIZE +#define VCPU_RCX (SVM_vcpu_arch_regs + __VCPU_REGS_RCX * WORD_SIZE) +#define VCPU_RDX (SVM_vcpu_arch_regs + __VCPU_REGS_RDX * WORD_SIZE) +#define VCPU_RBX (SVM_vcpu_arch_regs + __VCPU_REGS_RBX * WORD_SIZE) /* Intentionally omit RSP as it's context switched by hardware */ -#define VCPU_RBP __VCPU_REGS_RBP * WORD_SIZE -#define VCPU_RSI __VCPU_REGS_RSI * WORD_SIZE -#define VCPU_RDI __VCPU_REGS_RDI * WORD_SIZE +#define VCPU_RBP (SVM_vcpu_arch_regs + __VCPU_REGS_RBP * WORD_SIZE) +#define VCPU_RSI (SVM_vcpu_arch_regs + __VCPU_REGS_RSI * WORD_SIZE) +#define VCPU_RDI (SVM_vcpu_arch_regs + __VCPU_REGS_RDI * WORD_SIZE) #ifdef CONFIG_X86_64 -#define VCPU_R8 __VCPU_REGS_R8 * WORD_SIZE -#define VCPU_R9 __VCPU_REGS_R9 * WORD_SIZE -#define VCPU_R10 __VCPU_REGS_R10 * WORD_SIZE -#define VCPU_R11 __VCPU_REGS_R11 * WORD_SIZE -#define VCPU_R12 __VCPU_REGS_R12 * WORD_SIZE -#define VCPU_R13 __VCPU_REGS_R13 * WORD_SIZE -#define VCPU_R14 __VCPU_REGS_R14 * WORD_SIZE -#define VCPU_R15 __VCPU_REGS_R15 * WORD_SIZE +#define VCPU_R8 (SVM_vcpu_arch_regs + __VCPU_REGS_R8 * WORD_SIZE) +#define VCPU_R9 (SVM_vcpu_arch_regs + __VCPU_REGS_R9 * WORD_SIZE) +#define VCPU_R10 (SVM_vcpu_arch_regs + __VCPU_REGS_R10 * WORD_SIZE) +#define VCPU_R11 (SVM_vcpu_arch_regs + __VCPU_REGS_R11 * WORD_SIZE) +#define VCPU_R12 (SVM_vcpu_arch_regs + __VCPU_REGS_R12 * WORD_SIZE) +#define VCPU_R13 (SVM_vcpu_arch_regs + __VCPU_REGS_R13 * WORD_SIZE) +#define VCPU_R14 (SVM_vcpu_arch_regs + __VCPU_REGS_R14 * WORD_SIZE) +#define VCPU_R15 (SVM_vcpu_arch_regs + __VCPU_REGS_R15 * WORD_SIZE) #endif .section .noinstr.text, "ax" @@ -32,7 +33,7 @@ /** * __svm_vcpu_run - Run a vCPU via a transition to SVM guest mode * @vmcb_pa: unsigned long - * @regs: unsigned long * (to guest registers) + * @svm: struct vcpu_svm * */ SYM_FUNC_START(__svm_vcpu_run) push %_ASM_BP @@ -47,13 +48,13 @@ SYM_FUNC_START(__svm_vcpu_run) #endif push %_ASM_BX - /* Save @regs. */ + /* Save @svm. */ push %_ASM_ARG2 /* Save @vmcb. */ push %_ASM_ARG1 - /* Move @regs to RAX. */ + /* Move @svm to RAX. */ mov %_ASM_ARG2, %_ASM_AX /* Load guest registers. */ @@ -89,7 +90,7 @@ SYM_FUNC_START(__svm_vcpu_run) FILL_RETURN_BUFFER %_ASM_AX, RSB_CLEAR_LOOPS, X86_FEATURE_RETPOLINE #endif - /* "POP" @regs to RAX. */ + /* "POP" @svm to RAX. */ pop %_ASM_AX /* Save all guest registers. */

2 years, 1 month

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FAILED: patch "[PATCH] KVM: SVM: replace regs argument of __svm_vcpu_run() with" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. Possible dependencies: 16fdc1de169e ("KVM: SVM: replace regs argument of __svm_vcpu_run() with vcpu_svm") debc5a1ec0d1 ("KVM: x86: use a separate asm-offsets.c file") bb06650634d3 ("KVM: VMX: Convert launched argument to flags") 8bd200d23ec4 ("KVM: VMX: Flatten __vmx_vcpu_run()") 527a534c7326 ("x86/tdx: Provide common base for SEAMCALL and TDCALL C wrappers") 59bd54a84d15 ("x86/tdx: Detect running as a TDX guest in early boot") 6198311093da ("x86/cc: Move arch/x86/{kernel/cc_platform.c => coco/core.c}") f94909ceb1ed ("x86: Prepare asm files for straight-line-speculation") 22da5a07c75e ("x86/lib/atomic64_386_32: Rename things") 1367afaa2ee9 ("x86/entry: Use the correct fence macro after swapgs in kernel CR3") c07e45553da1 ("x86/entry: Add a fence for kernel entry SWAPGS in paranoid_entry()") 6e5772c8d9cf ("Merge tag 'x86_cc_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 16fdc1de169ee0a4e59a8c02244414ec7acd55c3 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini <pbonzini(a)redhat.com> Date: Fri, 30 Sep 2022 14:14:44 -0400 Subject: [PATCH] KVM: SVM: replace regs argument of __svm_vcpu_run() with vcpu_svm Since registers are reachable through vcpu_svm, and we will need to access more fields of that struct, pass it instead of the regs[] array. No functional change intended. Cc: stable(a)vger.kernel.org Fixes: a149180fbcf3 ("x86: Add magic AMD return-thunk") Reviewed-by: Sean Christopherson <seanjc(a)google.com> Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> diff --git a/arch/x86/kvm/Makefile b/arch/x86/kvm/Makefile index a02cf9baacc8..f453a0f96e24 100644 --- a/arch/x86/kvm/Makefile +++ b/arch/x86/kvm/Makefile @@ -35,6 +35,9 @@ obj-$(CONFIG_KVM) += kvm.o obj-$(CONFIG_KVM_INTEL) += kvm-intel.o obj-$(CONFIG_KVM_AMD) += kvm-amd.o +AFLAGS_svm/vmenter.o := -iquote $(obj) +$(obj)/svm/vmenter.o: $(obj)/kvm-asm-offsets.h + AFLAGS_vmx/vmenter.o := -iquote $(obj) $(obj)/vmx/vmenter.o: $(obj)/kvm-asm-offsets.h diff --git a/arch/x86/kvm/kvm-asm-offsets.c b/arch/x86/kvm/kvm-asm-offsets.c index 9d84f2b32d7f..30db96852e2d 100644 --- a/arch/x86/kvm/kvm-asm-offsets.c +++ b/arch/x86/kvm/kvm-asm-offsets.c @@ -8,9 +8,15 @@ #include <linux/kbuild.h> #include "vmx/vmx.h" +#include "svm/svm.h" static void __used common(void) { + if (IS_ENABLED(CONFIG_KVM_AMD)) { + BLANK(); + OFFSET(SVM_vcpu_arch_regs, vcpu_svm, vcpu.arch.regs); + } + if (IS_ENABLED(CONFIG_KVM_INTEL)) { BLANK(); OFFSET(VMX_spec_ctrl, vcpu_vmx, spec_ctrl); diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 58f0077d9357..b412bc5773c5 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -3930,7 +3930,7 @@ static noinstr void svm_vcpu_enter_exit(struct kvm_vcpu *vcpu) * vmcb02 when switching vmcbs for nested virtualization. */ vmload(svm->vmcb01.pa); - __svm_vcpu_run(vmcb_pa, (unsigned long *)&vcpu->arch.regs); + __svm_vcpu_run(vmcb_pa, svm); vmsave(svm->vmcb01.pa); vmload(__sme_page_pa(sd->save_area)); diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index 6a7686bf6900..447e25c9101a 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -684,6 +684,6 @@ void sev_es_unmap_ghcb(struct vcpu_svm *svm); /* vmenter.S */ void __svm_sev_es_vcpu_run(unsigned long vmcb_pa); -void __svm_vcpu_run(unsigned long vmcb_pa, unsigned long *regs); +void __svm_vcpu_run(unsigned long vmcb_pa, struct vcpu_svm *svm); #endif diff --git a/arch/x86/kvm/svm/vmenter.S b/arch/x86/kvm/svm/vmenter.S index 723f8534986c..f0ff41103e4c 100644 --- a/arch/x86/kvm/svm/vmenter.S +++ b/arch/x86/kvm/svm/vmenter.S @@ -4,27 +4,28 @@ #include <asm/bitsperlong.h> #include <asm/kvm_vcpu_regs.h> #include <asm/nospec-branch.h> +#include "kvm-asm-offsets.h" #define WORD_SIZE (BITS_PER_LONG / 8) /* Intentionally omit RAX as it's context switched by hardware */ -#define VCPU_RCX __VCPU_REGS_RCX * WORD_SIZE -#define VCPU_RDX __VCPU_REGS_RDX * WORD_SIZE -#define VCPU_RBX __VCPU_REGS_RBX * WORD_SIZE +#define VCPU_RCX (SVM_vcpu_arch_regs + __VCPU_REGS_RCX * WORD_SIZE) +#define VCPU_RDX (SVM_vcpu_arch_regs + __VCPU_REGS_RDX * WORD_SIZE) +#define VCPU_RBX (SVM_vcpu_arch_regs + __VCPU_REGS_RBX * WORD_SIZE) /* Intentionally omit RSP as it's context switched by hardware */ -#define VCPU_RBP __VCPU_REGS_RBP * WORD_SIZE -#define VCPU_RSI __VCPU_REGS_RSI * WORD_SIZE -#define VCPU_RDI __VCPU_REGS_RDI * WORD_SIZE +#define VCPU_RBP (SVM_vcpu_arch_regs + __VCPU_REGS_RBP * WORD_SIZE) +#define VCPU_RSI (SVM_vcpu_arch_regs + __VCPU_REGS_RSI * WORD_SIZE) +#define VCPU_RDI (SVM_vcpu_arch_regs + __VCPU_REGS_RDI * WORD_SIZE) #ifdef CONFIG_X86_64 -#define VCPU_R8 __VCPU_REGS_R8 * WORD_SIZE -#define VCPU_R9 __VCPU_REGS_R9 * WORD_SIZE -#define VCPU_R10 __VCPU_REGS_R10 * WORD_SIZE -#define VCPU_R11 __VCPU_REGS_R11 * WORD_SIZE -#define VCPU_R12 __VCPU_REGS_R12 * WORD_SIZE -#define VCPU_R13 __VCPU_REGS_R13 * WORD_SIZE -#define VCPU_R14 __VCPU_REGS_R14 * WORD_SIZE -#define VCPU_R15 __VCPU_REGS_R15 * WORD_SIZE +#define VCPU_R8 (SVM_vcpu_arch_regs + __VCPU_REGS_R8 * WORD_SIZE) +#define VCPU_R9 (SVM_vcpu_arch_regs + __VCPU_REGS_R9 * WORD_SIZE) +#define VCPU_R10 (SVM_vcpu_arch_regs + __VCPU_REGS_R10 * WORD_SIZE) +#define VCPU_R11 (SVM_vcpu_arch_regs + __VCPU_REGS_R11 * WORD_SIZE) +#define VCPU_R12 (SVM_vcpu_arch_regs + __VCPU_REGS_R12 * WORD_SIZE) +#define VCPU_R13 (SVM_vcpu_arch_regs + __VCPU_REGS_R13 * WORD_SIZE) +#define VCPU_R14 (SVM_vcpu_arch_regs + __VCPU_REGS_R14 * WORD_SIZE) +#define VCPU_R15 (SVM_vcpu_arch_regs + __VCPU_REGS_R15 * WORD_SIZE) #endif .section .noinstr.text, "ax" @@ -32,7 +33,7 @@ /** * __svm_vcpu_run - Run a vCPU via a transition to SVM guest mode * @vmcb_pa: unsigned long - * @regs: unsigned long * (to guest registers) + * @svm: struct vcpu_svm * */ SYM_FUNC_START(__svm_vcpu_run) push %_ASM_BP @@ -47,13 +48,13 @@ SYM_FUNC_START(__svm_vcpu_run) #endif push %_ASM_BX - /* Save @regs. */ + /* Save @svm. */ push %_ASM_ARG2 /* Save @vmcb. */ push %_ASM_ARG1 - /* Move @regs to RAX. */ + /* Move @svm to RAX. */ mov %_ASM_ARG2, %_ASM_AX /* Load guest registers. */ @@ -89,7 +90,7 @@ SYM_FUNC_START(__svm_vcpu_run) FILL_RETURN_BUFFER %_ASM_AX, RSB_CLEAR_LOOPS, X86_FEATURE_RETPOLINE #endif - /* "POP" @regs to RAX. */ + /* "POP" @svm to RAX. */ pop %_ASM_AX /* Save all guest registers. */

2 years, 1 month

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FAILED: patch "[PATCH] KVM: x86: use a separate asm-offsets.c file" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. Possible dependencies: debc5a1ec0d1 ("KVM: x86: use a separate asm-offsets.c file") bb06650634d3 ("KVM: VMX: Convert launched argument to flags") 8bd200d23ec4 ("KVM: VMX: Flatten __vmx_vcpu_run()") 527a534c7326 ("x86/tdx: Provide common base for SEAMCALL and TDCALL C wrappers") 59bd54a84d15 ("x86/tdx: Detect running as a TDX guest in early boot") 6198311093da ("x86/cc: Move arch/x86/{kernel/cc_platform.c => coco/core.c}") f94909ceb1ed ("x86: Prepare asm files for straight-line-speculation") 22da5a07c75e ("x86/lib/atomic64_386_32: Rename things") 1367afaa2ee9 ("x86/entry: Use the correct fence macro after swapgs in kernel CR3") c07e45553da1 ("x86/entry: Add a fence for kernel entry SWAPGS in paranoid_entry()") 6e5772c8d9cf ("Merge tag 'x86_cc_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From debc5a1ec0d195ffea70d11efeffb713de9fdbc7 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini <pbonzini(a)redhat.com> Date: Tue, 8 Nov 2022 09:44:53 +0100 Subject: [PATCH] KVM: x86: use a separate asm-offsets.c file This already removes an ugly #include "" from asm-offsets.c, but especially it avoids a future error when trying to define asm-offsets for KVM's svm/svm.h header. This would not work for kernel/asm-offsets.c, because svm/svm.h includes kvm_cache_regs.h which is not in the include path when compiling asm-offsets.c. The problem is not there if the .c file is in arch/x86/kvm. Suggested-by: Sean Christopherson <seanjc(a)google.com> Cc: stable(a)vger.kernel.org Fixes: a149180fbcf3 ("x86: Add magic AMD return-thunk") Reviewed-by: Sean Christopherson <seanjc(a)google.com> Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> diff --git a/arch/x86/kernel/asm-offsets.c b/arch/x86/kernel/asm-offsets.c index cb50589a7102..437308004ef2 100644 --- a/arch/x86/kernel/asm-offsets.c +++ b/arch/x86/kernel/asm-offsets.c @@ -19,7 +19,6 @@ #include <asm/suspend.h> #include <asm/tlbflush.h> #include <asm/tdx.h> -#include "../kvm/vmx/vmx.h" #ifdef CONFIG_XEN #include <xen/interface/xen.h> @@ -108,9 +107,4 @@ static void __used common(void) OFFSET(TSS_sp0, tss_struct, x86_tss.sp0); OFFSET(TSS_sp1, tss_struct, x86_tss.sp1); OFFSET(TSS_sp2, tss_struct, x86_tss.sp2); - - if (IS_ENABLED(CONFIG_KVM_INTEL)) { - BLANK(); - OFFSET(VMX_spec_ctrl, vcpu_vmx, spec_ctrl); - } } diff --git a/arch/x86/kvm/.gitignore b/arch/x86/kvm/.gitignore new file mode 100644 index 000000000000..615d6ff35c00 --- /dev/null +++ b/arch/x86/kvm/.gitignore @@ -0,0 +1,2 @@ +/kvm-asm-offsets.s +/kvm-asm-offsets.h diff --git a/arch/x86/kvm/Makefile b/arch/x86/kvm/Makefile index 30f244b64523..a02cf9baacc8 100644 --- a/arch/x86/kvm/Makefile +++ b/arch/x86/kvm/Makefile @@ -34,3 +34,12 @@ endif obj-$(CONFIG_KVM) += kvm.o obj-$(CONFIG_KVM_INTEL) += kvm-intel.o obj-$(CONFIG_KVM_AMD) += kvm-amd.o + +AFLAGS_vmx/vmenter.o := -iquote $(obj) +$(obj)/vmx/vmenter.o: $(obj)/kvm-asm-offsets.h + +$(obj)/kvm-asm-offsets.h: $(obj)/kvm-asm-offsets.s FORCE + $(call filechk,offsets,__KVM_ASM_OFFSETS_H__) + +targets += kvm-asm-offsets.s +clean-files += kvm-asm-offsets.h diff --git a/arch/x86/kvm/kvm-asm-offsets.c b/arch/x86/kvm/kvm-asm-offsets.c new file mode 100644 index 000000000000..9d84f2b32d7f --- /dev/null +++ b/arch/x86/kvm/kvm-asm-offsets.c @@ -0,0 +1,18 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Generate definitions needed by assembly language modules. + * This code generates raw asm output which is post-processed to extract + * and format the required data. + */ +#define COMPILE_OFFSETS + +#include <linux/kbuild.h> +#include "vmx/vmx.h" + +static void __used common(void) +{ + if (IS_ENABLED(CONFIG_KVM_INTEL)) { + BLANK(); + OFFSET(VMX_spec_ctrl, vcpu_vmx, spec_ctrl); + } +} diff --git a/arch/x86/kvm/vmx/vmenter.S b/arch/x86/kvm/vmx/vmenter.S index 8477d8bdd69c..0b5db4de4d09 100644 --- a/arch/x86/kvm/vmx/vmenter.S +++ b/arch/x86/kvm/vmx/vmenter.S @@ -1,12 +1,12 @@ /* SPDX-License-Identifier: GPL-2.0 */ #include <linux/linkage.h> #include <asm/asm.h> -#include <asm/asm-offsets.h> #include <asm/bitsperlong.h> #include <asm/kvm_vcpu_regs.h> #include <asm/nospec-branch.h> #include <asm/percpu.h> #include <asm/segment.h> +#include "kvm-asm-offsets.h" #include "run_flags.h" #define WORD_SIZE (BITS_PER_LONG / 8)

2 years, 1 month

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FAILED: patch "[PATCH] KVM: x86: use a separate asm-offsets.c file" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. Possible dependencies: debc5a1ec0d1 ("KVM: x86: use a separate asm-offsets.c file") bb06650634d3 ("KVM: VMX: Convert launched argument to flags") 8bd200d23ec4 ("KVM: VMX: Flatten __vmx_vcpu_run()") 527a534c7326 ("x86/tdx: Provide common base for SEAMCALL and TDCALL C wrappers") 59bd54a84d15 ("x86/tdx: Detect running as a TDX guest in early boot") 6198311093da ("x86/cc: Move arch/x86/{kernel/cc_platform.c => coco/core.c}") f94909ceb1ed ("x86: Prepare asm files for straight-line-speculation") 22da5a07c75e ("x86/lib/atomic64_386_32: Rename things") 1367afaa2ee9 ("x86/entry: Use the correct fence macro after swapgs in kernel CR3") c07e45553da1 ("x86/entry: Add a fence for kernel entry SWAPGS in paranoid_entry()") 6e5772c8d9cf ("Merge tag 'x86_cc_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From debc5a1ec0d195ffea70d11efeffb713de9fdbc7 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini <pbonzini(a)redhat.com> Date: Tue, 8 Nov 2022 09:44:53 +0100 Subject: [PATCH] KVM: x86: use a separate asm-offsets.c file This already removes an ugly #include "" from asm-offsets.c, but especially it avoids a future error when trying to define asm-offsets for KVM's svm/svm.h header. This would not work for kernel/asm-offsets.c, because svm/svm.h includes kvm_cache_regs.h which is not in the include path when compiling asm-offsets.c. The problem is not there if the .c file is in arch/x86/kvm. Suggested-by: Sean Christopherson <seanjc(a)google.com> Cc: stable(a)vger.kernel.org Fixes: a149180fbcf3 ("x86: Add magic AMD return-thunk") Reviewed-by: Sean Christopherson <seanjc(a)google.com> Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> diff --git a/arch/x86/kernel/asm-offsets.c b/arch/x86/kernel/asm-offsets.c index cb50589a7102..437308004ef2 100644 --- a/arch/x86/kernel/asm-offsets.c +++ b/arch/x86/kernel/asm-offsets.c @@ -19,7 +19,6 @@ #include <asm/suspend.h> #include <asm/tlbflush.h> #include <asm/tdx.h> -#include "../kvm/vmx/vmx.h" #ifdef CONFIG_XEN #include <xen/interface/xen.h> @@ -108,9 +107,4 @@ static void __used common(void) OFFSET(TSS_sp0, tss_struct, x86_tss.sp0); OFFSET(TSS_sp1, tss_struct, x86_tss.sp1); OFFSET(TSS_sp2, tss_struct, x86_tss.sp2); - - if (IS_ENABLED(CONFIG_KVM_INTEL)) { - BLANK(); - OFFSET(VMX_spec_ctrl, vcpu_vmx, spec_ctrl); - } } diff --git a/arch/x86/kvm/.gitignore b/arch/x86/kvm/.gitignore new file mode 100644 index 000000000000..615d6ff35c00 --- /dev/null +++ b/arch/x86/kvm/.gitignore @@ -0,0 +1,2 @@ +/kvm-asm-offsets.s +/kvm-asm-offsets.h diff --git a/arch/x86/kvm/Makefile b/arch/x86/kvm/Makefile index 30f244b64523..a02cf9baacc8 100644 --- a/arch/x86/kvm/Makefile +++ b/arch/x86/kvm/Makefile @@ -34,3 +34,12 @@ endif obj-$(CONFIG_KVM) += kvm.o obj-$(CONFIG_KVM_INTEL) += kvm-intel.o obj-$(CONFIG_KVM_AMD) += kvm-amd.o + +AFLAGS_vmx/vmenter.o := -iquote $(obj) +$(obj)/vmx/vmenter.o: $(obj)/kvm-asm-offsets.h + +$(obj)/kvm-asm-offsets.h: $(obj)/kvm-asm-offsets.s FORCE + $(call filechk,offsets,__KVM_ASM_OFFSETS_H__) + +targets += kvm-asm-offsets.s +clean-files += kvm-asm-offsets.h diff --git a/arch/x86/kvm/kvm-asm-offsets.c b/arch/x86/kvm/kvm-asm-offsets.c new file mode 100644 index 000000000000..9d84f2b32d7f --- /dev/null +++ b/arch/x86/kvm/kvm-asm-offsets.c @@ -0,0 +1,18 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Generate definitions needed by assembly language modules. + * This code generates raw asm output which is post-processed to extract + * and format the required data. + */ +#define COMPILE_OFFSETS + +#include <linux/kbuild.h> +#include "vmx/vmx.h" + +static void __used common(void) +{ + if (IS_ENABLED(CONFIG_KVM_INTEL)) { + BLANK(); + OFFSET(VMX_spec_ctrl, vcpu_vmx, spec_ctrl); + } +} diff --git a/arch/x86/kvm/vmx/vmenter.S b/arch/x86/kvm/vmx/vmenter.S index 8477d8bdd69c..0b5db4de4d09 100644 --- a/arch/x86/kvm/vmx/vmenter.S +++ b/arch/x86/kvm/vmx/vmenter.S @@ -1,12 +1,12 @@ /* SPDX-License-Identifier: GPL-2.0 */ #include <linux/linkage.h> #include <asm/asm.h> -#include <asm/asm-offsets.h> #include <asm/bitsperlong.h> #include <asm/kvm_vcpu_regs.h> #include <asm/nospec-branch.h> #include <asm/percpu.h> #include <asm/segment.h> +#include "kvm-asm-offsets.h" #include "run_flags.h" #define WORD_SIZE (BITS_PER_LONG / 8)

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Linux-stable-mirror November 2022