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| author |   Gleb Natapov <gleb@redhat.com> | 2013-01-21 15:36:49 +0200 |
|---|---|---|
| committer |   Marcelo Tosatti <mtosatti@redhat.com> | 2013-01-24 00:40:31 -0200 |
| commit | 141687869fb904e912568c6b94a6b1fa2114f6ed (patch) | |
| tree | 6c2c62b50e8b499db77ecb5f1b1d1570f06d49a8 /arch/x86/kvm | |
| parent | KVM: x86: fix use of uninitialized memory as segment descriptor in emulator. (diff) | |
| download | linux-dev-141687869fb904e912568c6b94a6b1fa2114f6ed.tar.xz linux-dev-141687869fb904e912568c6b94a6b1fa2114f6ed.zip | |
KVM: VMX: set vmx->emulation_required only when needed.
If emulate_invalid_guest_state=false vmx->emulation_required is never
actually used, but it ends up to be always set to true since
handle_invalid_guest_state(), the only place it is reset back to
false, is never called. This, besides been not very clean, makes vmexit
and vmentry path to check emulate_invalid_guest_state needlessly.
The patch fixes that by keeping emulation_required coherent with
emulate_invalid_guest_state setting.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to 'arch/x86/kvm')
| -rw-r--r-- | arch/x86/kvm/vmx.c | 19 |
1 files changed, 12 insertions, 7 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 9bc68c7bca7d..02eeba86328d 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -2759,6 +2759,11 @@ static __exit void hardware_unsetup(void) free_kvm_area(); } +static bool emulation_required(struct kvm_vcpu *vcpu) +{ + return emulate_invalid_guest_state && !guest_state_valid(vcpu); +} + static void fix_pmode_seg(struct kvm_vcpu *vcpu, int seg, struct kvm_segment *save) { @@ -2794,7 +2799,6 @@ static void enter_pmode(struct kvm_vcpu *vcpu) vmx_get_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_SS], VCPU_SREG_SS); vmx_get_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_CS], VCPU_SREG_CS); - vmx->emulation_required = 1; vmx->rmode.vm86_active = 0; vmx_segment_cache_clear(vmx); @@ -2885,7 +2889,6 @@ static void enter_rmode(struct kvm_vcpu *vcpu) vmx_get_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_SS], VCPU_SREG_SS); vmx_get_segment(vcpu, &vmx->rmode.segs[VCPU_SREG_CS], VCPU_SREG_CS); - vmx->emulation_required = 1; vmx->rmode.vm86_active = 1; /* @@ -3111,6 +3114,9 @@ static void vmx_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0) vmcs_writel(CR0_READ_SHADOW, cr0); vmcs_writel(GUEST_CR0, hw_cr0); vcpu->arch.cr0 = cr0; + + /* depends on vcpu->arch.cr0 to be set to a new value */ + vmx->emulation_required = emulation_required(vcpu); } static u64 construct_eptp(unsigned long root_hpa) @@ -3298,8 +3304,7 @@ static void vmx_set_segment(struct kvm_vcpu *vcpu, vmcs_write32(sf->ar_bytes, vmx_segment_access_rights(var)); out: - if (!vmx->emulation_required) - vmx->emulation_required = !guest_state_valid(vcpu); + vmx->emulation_required |= emulation_required(vcpu); } static void vmx_get_cs_db_l_bits(struct kvm_vcpu *vcpu, int *db, int *l) @@ -5027,7 +5032,7 @@ static int handle_invalid_guest_state(struct kvm_vcpu *vcpu) schedule(); } - vmx->emulation_required = !guest_state_valid(vcpu); + vmx->emulation_required = emulation_required(vcpu); out: return ret; } @@ -5970,7 +5975,7 @@ static int vmx_handle_exit(struct kvm_vcpu *vcpu) u32 vectoring_info = vmx->idt_vectoring_info; /* If guest state is invalid, start emulating */ - if (vmx->emulation_required && emulate_invalid_guest_state) + if (vmx->emulation_required) return handle_invalid_guest_state(vcpu); /* @@ -6253,7 +6258,7 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu) /* Don't enter VMX if guest state is invalid, let the exit handler start emulation until we arrive back to a valid state */ - if (vmx->emulation_required && emulate_invalid_guest_state) + if (vmx->emulation_required) return; if (test_bit(VCPU_REGS_RSP, (unsigned long *)&vcpu->arch.regs_dirty)) |