diff options
| author | Sean Christopherson <seanjc@google.com> | 2021-07-13 09:33:06 -0700 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-08-02 11:01:55 -0400 |
| commit | 1dd7a4f18fbcc0db1acc07df5c1ae8ba4ce10593 (patch) | |
| tree | d8dbbc467e9f603069e936ab120a6d72fae3754b /arch/x86 | |
| parent | 32437c2aea428f9c3479904e342b02f5eee3a7f6 (diff) | |
KVM: VMX: Skip emulation required checks during pmode/rmode transitions
Don't refresh "emulation required" when stuffing segments during
transitions to/from real mode when running without unrestricted guest.
The checks are unnecessary as vmx_set_cr0() unconditionally rechecks
"emulation required". They also happen to be broken, as enter_pmode()
and enter_rmode() run with a stale vcpu->arch.cr0.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210713163324.627647-29-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kvm/vmx/vmx.c | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index aa547100f0df..ff3f75105ae9 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -2719,6 +2719,8 @@ static __init int alloc_kvm_area(void) return 0; } +static void __vmx_set_segment(struct kvm_vcpu *vcpu, struct kvm_segment *var, int seg); + static void fix_pmode_seg(struct kvm_vcpu *vcpu, int seg, struct kvm_segment *save) { @@ -2735,7 +2737,7 @@ static void fix_pmode_seg(struct kvm_vcpu *vcpu, int seg, save->dpl = save->selector & SEGMENT_RPL_MASK; save->s = 1; } - vmx_set_segment(vcpu, save, seg); + __vmx_set_segment(vcpu, save, seg); } static void enter_pmode(struct kvm_vcpu *vcpu) @@ -2756,7 +2758,7 @@ static void enter_pmode(struct kvm_vcpu *vcpu) vmx->rmode.vm86_active = 0; - vmx_set_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_TR], VCPU_SREG_TR); + __vmx_set_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_TR], VCPU_SREG_TR); flags = vmcs_readl(GUEST_RFLAGS); flags &= RMODE_GUEST_OWNED_EFLAGS_BITS; @@ -3291,7 +3293,7 @@ static u32 vmx_segment_access_rights(struct kvm_segment *var) return ar; } -void vmx_set_segment(struct kvm_vcpu *vcpu, struct kvm_segment *var, int seg) +static void __vmx_set_segment(struct kvm_vcpu *vcpu, struct kvm_segment *var, int seg) { struct vcpu_vmx *vmx = to_vmx(vcpu); const struct kvm_vmx_segment_field *sf = &kvm_vmx_segment_fields[seg]; @@ -3304,7 +3306,7 @@ void vmx_set_segment(struct kvm_vcpu *vcpu, struct kvm_segment *var, int seg) vmcs_write16(sf->selector, var->selector); else if (var->s) fix_rmode_seg(seg, &vmx->rmode.segs[seg]); - goto out; + return; } vmcs_writel(sf->base, var->base); @@ -3326,9 +3328,13 @@ void vmx_set_segment(struct kvm_vcpu *vcpu, struct kvm_segment *var, int seg) var->type |= 0x1; /* Accessed */ vmcs_write32(sf->ar_bytes, vmx_segment_access_rights(var)); +} -out: - vmx->emulation_required = emulation_required(vcpu); +void vmx_set_segment(struct kvm_vcpu *vcpu, struct kvm_segment *var, int seg) +{ + __vmx_set_segment(vcpu, var, seg); + + to_vmx(vcpu)->emulation_required = emulation_required(vcpu); } static void vmx_get_cs_db_l_bits(struct kvm_vcpu *vcpu, int *db, int *l) |