leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

KVM: x86: Replace late check_nested_events() hack with more precise fix

Browse Source 
Add an argument to interrupt_allowed and nmi_allowed, to checking if
interrupt injection is blocked.  Use the hook to handle the case where
an interrupt arrives between check_nested_events() and the injection
logic.  Drop the retry of check_nested_events() that hack-a-fixed the
same condition.

Blocking injection is also a bit of a hack, e.g. KVM should do exiting
and non-exiting interrupt processing in a single pass, but it's a more
precise hack.  The old comment is also misleading, e.g. KVM_REQ_EVENT is
purely an optimization, setting it on every run loop (which KVM doesn't
do) should not affect functionality, only performance.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200423022550.15113-13-sean.j.christopherson@intel.com>
[Extend to SVM, add SMI and NMI.  Even though NMI and SMI cannot come
 asynchronously right now, making the fix generic is easy and removes a
 special case. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini
2020-04-23 14:08:58 -04:00
parent 7ab0abdb55
commit c300ab9f08
4 changed files with 49 additions and 35 deletions
Download Patch File Download Diff File Expand all files Collapse all files

25
arch/x86/kvm/svm/svm.c
View File

@@ -3083,13 +3083,17 @@ bool svm_nmi_blocked(struct kvm_vcpu *vcpu)
return ret;
}
static bool svm_nmi_allowed(struct kvm_vcpu *vcpu)
static bool svm_nmi_allowed(struct kvm_vcpu *vcpu, bool for_injection)
{
struct vcpu_svm *svm = to_svm(vcpu);
if (svm->nested.nested_run_pending)
return false;
return !svm_nmi_blocked(vcpu);
/* An NMI must not be injected into L2 if it's supposed to VM-Exit. */
if (for_injection && is_guest_mode(vcpu) && nested_exit_on_nmi(svm))
return false;
return !svm_nmi_blocked(vcpu);
}
static bool svm_get_nmi_mask(struct kvm_vcpu *vcpu)
@@ -3138,13 +3142,20 @@ bool svm_interrupt_blocked(struct kvm_vcpu *vcpu)
return (vmcb->control.int_state & SVM_INTERRUPT_SHADOW_MASK);
}
static bool svm_interrupt_allowed(struct kvm_vcpu *vcpu)
static bool svm_interrupt_allowed(struct kvm_vcpu *vcpu, bool for_injection)
{
struct vcpu_svm *svm = to_svm(vcpu);
if (svm->nested.nested_run_pending)
return false;
return !svm_interrupt_blocked(vcpu);
/*
* An IRQ must not be injected into L2 if it's supposed to VM-Exit,
* e.g. if the IRQ arrived asynchronously after checking nested events.
*/
if (for_injection && is_guest_mode(vcpu) && nested_exit_on_intr(svm))
return false;
return !svm_interrupt_blocked(vcpu);
}
static void enable_irq_window(struct kvm_vcpu *vcpu)
@@ -3812,12 +3823,16 @@ bool svm_smi_blocked(struct kvm_vcpu *vcpu)
return is_smm(vcpu);
}
static bool svm_smi_allowed(struct kvm_vcpu *vcpu)
static bool svm_smi_allowed(struct kvm_vcpu *vcpu, bool for_injection)
{
struct vcpu_svm *svm = to_svm(vcpu);
if (svm->nested.nested_run_pending)
return false;
/* An SMI must not be injected into L2 if it's supposed to VM-Exit. */
if (for_injection && is_guest_mode(vcpu) && nested_exit_on_smi(svm))
return false;
return !svm_smi_blocked(vcpu);
}