6.6-stable review patch. If anyone has any objections, please let me know.
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From: Sean Christopherson seanjc@google.com
[ Upstream commit 0ec3d6d1f169baa7fc512ae4b78d17e7c94b7763 ]
Now that vmx->req_immediate_exit is used only in the scope of vmx_vcpu_run(), use force_immediate_exit to detect that KVM should usurp the VMX preemption to force a VM-Exit and let vendor code fully handle forcing a VM-Exit.
Opportunsitically drop __kvm_request_immediate_exit() and just have vendor code call smp_send_reschedule() directly. SVM already does this when injecting an event while also trying to single-step an IRET, i.e. it's not exactly secret knowledge that KVM uses a reschedule IPI to force an exit.
Link: https://lore.kernel.org/r/20240110012705.506918-7-seanjc@google.com Signed-off-by: Sean Christopherson seanjc@google.com [sean: resolve absurd conflict due to funky kvm_x86_ops.sched_in prototype] Signed-off-by: Sean Christopherson seanjc@google.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/include/asm/kvm-x86-ops.h | 1 - arch/x86/include/asm/kvm_host.h | 3 --- arch/x86/kvm/svm/svm.c | 7 ++++--- arch/x86/kvm/vmx/vmx.c | 32 +++++++++++++----------------- arch/x86/kvm/vmx/vmx.h | 2 -- arch/x86/kvm/x86.c | 10 +--------- 6 files changed, 19 insertions(+), 36 deletions(-)
diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h index e59ded976166..8fe6667d945f 100644 --- a/arch/x86/include/asm/kvm-x86-ops.h +++ b/arch/x86/include/asm/kvm-x86-ops.h @@ -102,7 +102,6 @@ KVM_X86_OP(write_tsc_multiplier) KVM_X86_OP(get_exit_info) KVM_X86_OP(check_intercept) KVM_X86_OP(handle_exit_irqoff) -KVM_X86_OP(request_immediate_exit) KVM_X86_OP(sched_in) KVM_X86_OP_OPTIONAL(update_cpu_dirty_logging) KVM_X86_OP_OPTIONAL(vcpu_blocking) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 5703600a454e..8898ad8cb3de 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1695,8 +1695,6 @@ struct kvm_x86_ops { struct x86_exception *exception); void (*handle_exit_irqoff)(struct kvm_vcpu *vcpu);
- void (*request_immediate_exit)(struct kvm_vcpu *vcpu); - void (*sched_in)(struct kvm_vcpu *kvm, int cpu);
/* @@ -2182,7 +2180,6 @@ extern bool kvm_find_async_pf_gfn(struct kvm_vcpu *vcpu, gfn_t gfn);
int kvm_skip_emulated_instruction(struct kvm_vcpu *vcpu); int kvm_complete_insn_gp(struct kvm_vcpu *vcpu, int err); -void __kvm_request_immediate_exit(struct kvm_vcpu *vcpu);
void __user *__x86_set_memory_region(struct kvm *kvm, int id, gpa_t gpa, u32 size); diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index f42c6ef7dc20..4a53b38ea386 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -4222,9 +4222,12 @@ static __no_kcsan fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu, * is enough to force an immediate vmexit. */ disable_nmi_singlestep(svm); - smp_send_reschedule(vcpu->cpu); + force_immediate_exit = true; }
+ if (force_immediate_exit) + smp_send_reschedule(vcpu->cpu); + pre_svm_run(vcpu);
sync_lapic_to_cr8(vcpu); @@ -5075,8 +5078,6 @@ static struct kvm_x86_ops svm_x86_ops __initdata = { .check_intercept = svm_check_intercept, .handle_exit_irqoff = svm_handle_exit_irqoff,
- .request_immediate_exit = __kvm_request_immediate_exit, - .sched_in = svm_sched_in,
.nested_ops = &svm_nested_ops, diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 0ecc0e996386..704e5a552b4f 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -49,6 +49,8 @@ #include <asm/spec-ctrl.h> #include <asm/vmx.h>
+#include <trace/events/ipi.h> + #include "capabilities.h" #include "cpuid.h" #include "hyperv.h" @@ -1304,8 +1306,6 @@ void vmx_prepare_switch_to_guest(struct kvm_vcpu *vcpu) u16 fs_sel, gs_sel; int i;
- vmx->req_immediate_exit = false; - /* * Note that guest MSRs to be saved/restored can also be changed * when guest state is loaded. This happens when guest transitions @@ -6015,7 +6015,8 @@ static int handle_pml_full(struct kvm_vcpu *vcpu) return 1; }
-static fastpath_t handle_fastpath_preemption_timer(struct kvm_vcpu *vcpu) +static fastpath_t handle_fastpath_preemption_timer(struct kvm_vcpu *vcpu, + bool force_immediate_exit) { struct vcpu_vmx *vmx = to_vmx(vcpu);
@@ -6031,7 +6032,7 @@ static fastpath_t handle_fastpath_preemption_timer(struct kvm_vcpu *vcpu) * If the timer expired because KVM used it to force an immediate exit, * then mission accomplished. */ - if (vmx->req_immediate_exit) + if (force_immediate_exit) return EXIT_FASTPATH_EXIT_HANDLED;
/* @@ -7210,13 +7211,13 @@ static void atomic_switch_perf_msrs(struct vcpu_vmx *vmx) msrs[i].host, false); }
-static void vmx_update_hv_timer(struct kvm_vcpu *vcpu) +static void vmx_update_hv_timer(struct kvm_vcpu *vcpu, bool force_immediate_exit) { struct vcpu_vmx *vmx = to_vmx(vcpu); u64 tscl; u32 delta_tsc;
- if (vmx->req_immediate_exit) { + if (force_immediate_exit) { vmcs_write32(VMX_PREEMPTION_TIMER_VALUE, 0); vmx->loaded_vmcs->hv_timer_soft_disabled = false; } else if (vmx->hv_deadline_tsc != -1) { @@ -7269,7 +7270,8 @@ void noinstr vmx_spec_ctrl_restore_host(struct vcpu_vmx *vmx, barrier_nospec(); }
-static fastpath_t vmx_exit_handlers_fastpath(struct kvm_vcpu *vcpu) +static fastpath_t vmx_exit_handlers_fastpath(struct kvm_vcpu *vcpu, + bool force_immediate_exit) { /* * If L2 is active, some VMX preemption timer exits can be handled in @@ -7283,7 +7285,7 @@ static fastpath_t vmx_exit_handlers_fastpath(struct kvm_vcpu *vcpu) case EXIT_REASON_MSR_WRITE: return handle_fastpath_set_msr_irqoff(vcpu); case EXIT_REASON_PREEMPTION_TIMER: - return handle_fastpath_preemption_timer(vcpu); + return handle_fastpath_preemption_timer(vcpu, force_immediate_exit); default: return EXIT_FASTPATH_NONE; } @@ -7425,7 +7427,9 @@ static fastpath_t vmx_vcpu_run(struct kvm_vcpu *vcpu, bool force_immediate_exit) vmx_passthrough_lbr_msrs(vcpu);
if (enable_preemption_timer) - vmx_update_hv_timer(vcpu); + vmx_update_hv_timer(vcpu, force_immediate_exit); + else if (force_immediate_exit) + smp_send_reschedule(vcpu->cpu);
kvm_wait_lapic_expire(vcpu);
@@ -7489,7 +7493,7 @@ static fastpath_t vmx_vcpu_run(struct kvm_vcpu *vcpu, bool force_immediate_exit) vmx_recover_nmi_blocking(vmx); vmx_complete_interrupts(vmx);
- return vmx_exit_handlers_fastpath(vcpu); + return vmx_exit_handlers_fastpath(vcpu, force_immediate_exit); }
static void vmx_vcpu_free(struct kvm_vcpu *vcpu) @@ -7988,11 +7992,6 @@ static __init void vmx_set_cpu_caps(void) kvm_cpu_cap_check_and_set(X86_FEATURE_WAITPKG); }
-static void vmx_request_immediate_exit(struct kvm_vcpu *vcpu) -{ - to_vmx(vcpu)->req_immediate_exit = true; -} - static int vmx_check_intercept_io(struct kvm_vcpu *vcpu, struct x86_instruction_info *info) { @@ -8404,8 +8403,6 @@ static struct kvm_x86_ops vmx_x86_ops __initdata = { .check_intercept = vmx_check_intercept, .handle_exit_irqoff = vmx_handle_exit_irqoff,
- .request_immediate_exit = vmx_request_immediate_exit, - .sched_in = vmx_sched_in,
.cpu_dirty_log_size = PML_ENTITY_NUM, @@ -8663,7 +8660,6 @@ static __init int hardware_setup(void) if (!enable_preemption_timer) { vmx_x86_ops.set_hv_timer = NULL; vmx_x86_ops.cancel_hv_timer = NULL; - vmx_x86_ops.request_immediate_exit = __kvm_request_immediate_exit; }
kvm_caps.supported_mce_cap |= MCG_LMCE_P; diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h index fb36bde2dd87..50d32d830890 100644 --- a/arch/x86/kvm/vmx/vmx.h +++ b/arch/x86/kvm/vmx/vmx.h @@ -331,8 +331,6 @@ struct vcpu_vmx { unsigned int ple_window; bool ple_window_dirty;
- bool req_immediate_exit; - /* Support for PML */ #define PML_ENTITY_NUM 512 struct page *pml_pg; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index d04066099567..f3150d9a1918 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -10505,12 +10505,6 @@ static void kvm_vcpu_reload_apic_access_page(struct kvm_vcpu *vcpu) static_call_cond(kvm_x86_set_apic_access_page_addr)(vcpu); }
-void __kvm_request_immediate_exit(struct kvm_vcpu *vcpu) -{ - smp_send_reschedule(vcpu->cpu); -} -EXPORT_SYMBOL_GPL(__kvm_request_immediate_exit); - /* * Called within kvm->srcu read side. * Returns 1 to let vcpu_run() continue the guest execution loop without @@ -10756,10 +10750,8 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) goto cancel_injection; }
- if (req_immediate_exit) { + if (req_immediate_exit) kvm_make_request(KVM_REQ_EVENT, vcpu); - static_call(kvm_x86_request_immediate_exit)(vcpu); - }
fpregs_assert_state_consistent(); if (test_thread_flag(TIF_NEED_FPU_LOAD))