diff options
| author | Avi Kivity <avi@redhat.com> | 2010-04-08 17:19:35 +0200 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2010-04-20 11:59:31 +0200 |
| commit | 78ac8b47c566dd6177a3b9b291b756ccb70670b7 (patch) | |
| tree | 46feb3a7845c7e4a3d0c621d17b3f2593e7d756f /arch | |
| parent | KVM: allow bit 10 to be cleared in MSR_IA32_MC4_CTL (diff) | |
| download | linux-78ac8b47c566dd6177a3b9b291b756ccb70670b7.tar.xz linux-78ac8b47c566dd6177a3b9b291b756ccb70670b7.zip | |
KVM: VMX: Save/restore rflags.vm correctly in real mode
Currently we set eflags.vm unconditionally when entering real mode emulation
through virtual-8086 mode, and clear it unconditionally when we enter protected
mode. The means that the following sequence
KVM_SET_REGS (rflags.vm=1)
KVM_SET_SREGS (cr0.pe=1)
Ends up with rflags.vm clear due to KVM_SET_SREGS triggering enter_pmode().
Fix by shadowing rflags.vm (and rflags.iopl) correctly while in real mode:
reads and writes to those bits access a shadow register instead of the actual
register.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to '')
| -rw-r--r-- | arch/x86/kvm/vmx.c | 24 |
1 files changed, 15 insertions, 9 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 686492ed3079..bc933cfb4e66 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -77,6 +77,8 @@ module_param(emulate_invalid_guest_state, bool, S_IRUGO); #define KVM_PMODE_VM_CR4_ALWAYS_ON (X86_CR4_PAE | X86_CR4_VMXE) #define KVM_RMODE_VM_CR4_ALWAYS_ON (X86_CR4_VME | X86_CR4_PAE | X86_CR4_VMXE) +#define RMODE_GUEST_OWNED_EFLAGS_BITS (~(X86_EFLAGS_IOPL | X86_EFLAGS_VM)) + /* * These 2 parameters are used to config the controls for Pause-Loop Exiting: * ple_gap: upper bound on the amount of time between two successive @@ -131,7 +133,7 @@ struct vcpu_vmx { } host_state; struct { int vm86_active; - u8 save_iopl; + ulong save_rflags; struct kvm_save_segment { u16 selector; unsigned long base; @@ -818,18 +820,23 @@ static void vmx_fpu_deactivate(struct kvm_vcpu *vcpu) static unsigned long vmx_get_rflags(struct kvm_vcpu *vcpu) { - unsigned long rflags; + unsigned long rflags, save_rflags; rflags = vmcs_readl(GUEST_RFLAGS); - if (to_vmx(vcpu)->rmode.vm86_active) - rflags &= ~(unsigned long)(X86_EFLAGS_IOPL | X86_EFLAGS_VM); + if (to_vmx(vcpu)->rmode.vm86_active) { + rflags &= RMODE_GUEST_OWNED_EFLAGS_BITS; + save_rflags = to_vmx(vcpu)->rmode.save_rflags; + rflags |= save_rflags & ~RMODE_GUEST_OWNED_EFLAGS_BITS; + } return rflags; } static void vmx_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags) { - if (to_vmx(vcpu)->rmode.vm86_active) + if (to_vmx(vcpu)->rmode.vm86_active) { + to_vmx(vcpu)->rmode.save_rflags = rflags; rflags |= X86_EFLAGS_IOPL | X86_EFLAGS_VM; + } vmcs_writel(GUEST_RFLAGS, rflags); } @@ -1483,8 +1490,8 @@ static void enter_pmode(struct kvm_vcpu *vcpu) vmcs_write32(GUEST_TR_AR_BYTES, vmx->rmode.tr.ar); flags = vmcs_readl(GUEST_RFLAGS); - flags &= ~(X86_EFLAGS_IOPL | X86_EFLAGS_VM); - flags |= (vmx->rmode.save_iopl << IOPL_SHIFT); + flags &= RMODE_GUEST_OWNED_EFLAGS_BITS; + flags |= vmx->rmode.save_rflags & ~RMODE_GUEST_OWNED_EFLAGS_BITS; vmcs_writel(GUEST_RFLAGS, flags); vmcs_writel(GUEST_CR4, (vmcs_readl(GUEST_CR4) & ~X86_CR4_VME) | @@ -1557,8 +1564,7 @@ static void enter_rmode(struct kvm_vcpu *vcpu) vmcs_write32(GUEST_TR_AR_BYTES, 0x008b); flags = vmcs_readl(GUEST_RFLAGS); - vmx->rmode.save_iopl - = (flags & X86_EFLAGS_IOPL) >> IOPL_SHIFT; + vmx->rmode.save_rflags = flags; flags |= X86_EFLAGS_IOPL | X86_EFLAGS_VM; |