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@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@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@vger.kernel.org Fixes: a149180fbcf3 ("x86: Add magic AMD return-thunk") Reviewed-by: Sean Christopherson seanjc@google.com Signed-off-by: Paolo Bonzini pbonzini@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