From b464f57e133d8c751ca1fb4af039c808b873876b Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Fri, 7 Jun 2019 19:00:14 +0200 Subject: [PATCH] KVM: VMX: simplify vmx_prepare_switch_to_{guest,host} vmx->loaded_cpu_state can only be NULL or equal to vmx->loaded_vmcs, so change it to a bool. Because the direction of the bool is now the opposite of vmx->guest_msrs_dirty, change the direction of vmx->guest_msrs_dirty so that they match. Finally, do not imply that MSRs have to be reloaded when vmx->guest_state_loaded is false; instead, set vmx->guest_msrs_ready to false explicitly in vmx_prepare_switch_to_host. Cc: Sean Christopherson Signed-off-by: Paolo Bonzini --- arch/x86/kvm/vmx/vmx.c | 26 +++++++++++++------------- arch/x86/kvm/vmx/vmx.h | 18 ++++++++++++------ 2 files changed, 25 insertions(+), 19 deletions(-) diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 091610684d28..02c54f684ce5 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -1057,20 +1057,18 @@ void vmx_prepare_switch_to_guest(struct kvm_vcpu *vcpu) * when guest state is loaded. This happens when guest transitions * to/from long-mode by setting MSR_EFER.LMA. */ - if (!vmx->loaded_cpu_state || vmx->guest_msrs_dirty) { - vmx->guest_msrs_dirty = false; + if (!vmx->guest_msrs_ready) { + vmx->guest_msrs_ready = true; for (i = 0; i < vmx->save_nmsrs; ++i) kvm_set_shared_msr(vmx->guest_msrs[i].index, vmx->guest_msrs[i].data, vmx->guest_msrs[i].mask); } - - if (vmx->loaded_cpu_state) + if (vmx->guest_state_loaded) return; - vmx->loaded_cpu_state = vmx->loaded_vmcs; - host_state = &vmx->loaded_cpu_state->host_state; + host_state = &vmx->loaded_vmcs->host_state; /* * Set host fs and gs selectors. Unfortunately, 22.2.3 does not @@ -1126,20 +1124,20 @@ void vmx_prepare_switch_to_guest(struct kvm_vcpu *vcpu) vmcs_writel(HOST_GS_BASE, gs_base); host_state->gs_base = gs_base; } + + vmx->guest_state_loaded = true; } static void vmx_prepare_switch_to_host(struct vcpu_vmx *vmx) { struct vmcs_host_state *host_state; - if (!vmx->loaded_cpu_state) + if (!vmx->guest_state_loaded) return; - WARN_ON_ONCE(vmx->loaded_cpu_state != vmx->loaded_vmcs); - host_state = &vmx->loaded_cpu_state->host_state; + host_state = &vmx->loaded_vmcs->host_state; ++vmx->vcpu.stat.host_state_reload; - vmx->loaded_cpu_state = NULL; #ifdef CONFIG_X86_64 rdmsrl(MSR_KERNEL_GS_BASE, vmx->msr_guest_kernel_gs_base); @@ -1165,13 +1163,15 @@ static void vmx_prepare_switch_to_host(struct vcpu_vmx *vmx) wrmsrl(MSR_KERNEL_GS_BASE, vmx->msr_host_kernel_gs_base); #endif load_fixmap_gdt(raw_smp_processor_id()); + vmx->guest_state_loaded = false; + vmx->guest_msrs_ready = false; } #ifdef CONFIG_X86_64 static u64 vmx_read_guest_kernel_gs_base(struct vcpu_vmx *vmx) { preempt_disable(); - if (vmx->loaded_cpu_state) + if (vmx->guest_state_loaded) rdmsrl(MSR_KERNEL_GS_BASE, vmx->msr_guest_kernel_gs_base); preempt_enable(); return vmx->msr_guest_kernel_gs_base; @@ -1180,7 +1180,7 @@ static u64 vmx_read_guest_kernel_gs_base(struct vcpu_vmx *vmx) static void vmx_write_guest_kernel_gs_base(struct vcpu_vmx *vmx, u64 data) { preempt_disable(); - if (vmx->loaded_cpu_state) + if (vmx->guest_state_loaded) wrmsrl(MSR_KERNEL_GS_BASE, data); preempt_enable(); vmx->msr_guest_kernel_gs_base = data; @@ -1583,7 +1583,7 @@ static void setup_msrs(struct vcpu_vmx *vmx) move_msr_up(vmx, index, save_nmsrs++); vmx->save_nmsrs = save_nmsrs; - vmx->guest_msrs_dirty = true; + vmx->guest_msrs_ready = false; if (cpu_has_vmx_msr_bitmap()) vmx_update_msr_bitmap(&vmx->vcpu); diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h index f03af64e9934..4c5c24f37c5f 100644 --- a/arch/x86/kvm/vmx/vmx.h +++ b/arch/x86/kvm/vmx/vmx.h @@ -187,13 +187,23 @@ struct vcpu_vmx { struct kvm_vcpu vcpu; u8 fail; u8 msr_bitmap_mode; + + /* + * If true, host state has been stored in vmx->loaded_vmcs for + * the CPU registers that only need to be switched when transitioning + * to/from the kernel, and the registers have been loaded with guest + * values. If false, host state is loaded in the CPU registers + * and vmx->loaded_vmcs->host_state is invalid. + */ + bool guest_state_loaded; + u32 exit_intr_info; u32 idt_vectoring_info; ulong rflags; struct shared_msr_entry *guest_msrs; int nmsrs; int save_nmsrs; - bool guest_msrs_dirty; + bool guest_msrs_ready; #ifdef CONFIG_X86_64 u64 msr_host_kernel_gs_base; u64 msr_guest_kernel_gs_base; @@ -208,14 +218,10 @@ struct vcpu_vmx { /* * loaded_vmcs points to the VMCS currently used in this vcpu. For a * non-nested (L1) guest, it always points to vmcs01. For a nested - * guest (L2), it points to a different VMCS. loaded_cpu_state points - * to the VMCS whose state is loaded into the CPU registers that only - * need to be switched when transitioning to/from the kernel; a NULL - * value indicates that host state is loaded. + * guest (L2), it points to a different VMCS. */ struct loaded_vmcs vmcs01; struct loaded_vmcs *loaded_vmcs; - struct loaded_vmcs *loaded_cpu_state; struct msr_autoload { struct vmx_msrs guest; -- 2.11.0