diff mbox

KVM: x86: keep EOI exit bitmap accurate before loading it.

Message ID 286AC319A985734F985F78AFA26841F77A280D@shsmsx102.ccr.corp.intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Wang, Wei W Aug. 26, 2014, 9:02 a.m. UTC 
Hi Alex,
Could you have a test if the two patches have solved the bug?

Thanks,
Wei

-----Original Message-----
From: Wang, Wei W 
Sent: Wednesday, August 27, 2014 12:28 AM
To: kvm@vger.kernel.org
Cc: pbonzini@redhat.com; alex.williamson@redhat.com; Wang, Wei W; Zhang, Yang Z
Subject: [PATCH] KVM: x86: keep EOI exit bitmap accurate before loading it.

Guest may mask the IOAPIC entry before issue EOI. In such case, EOI will not be intercepted by hypervisor, since the corrensponding bit in eoi exit bitmap is not set after the masking of IOAPIC entry.

The solution here is to OR EOI_exit_bitmap with tmr.

Tested-by: Rongrong Liu <rongrongx.liu@intel.com>
Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>
Signed-off-by: Wei Wang <wei.w.wang@intel.com>
---
 arch/x86/kvm/lapic.c |    9 +++++++++
 arch/x86/kvm/lapic.h |    2 ++
 arch/x86/kvm/x86.c   |    1 +
 virt/kvm/ioapic.c    |    6 +++---
 4 files changed, 15 insertions(+), 3 deletions(-)

--
1.7.1

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Comments

Alex Williamson Aug. 26, 2014, 9:01 p.m. UTC | #1 
On Tue, 2014-08-26 at 09:02 +0000, Wang, Wei W wrote:
> Hi Alex,
> Could you have a test if the two patches have solved the bug?

What case was missed by the previous single patch that is accounted for
now?  Some sort of comment in the update_tmr function would be nice to
explain the update, along with removing the unnecessary arrays as Paolo
pointed out, and I commented on in the previous version.  Thanks,

Alex

> -----Original Message-----
> From: Wang, Wei W 
> Sent: Wednesday, August 27, 2014 12:28 AM
> To: kvm@vger.kernel.org
> Cc: pbonzini@redhat.com; alex.williamson@redhat.com; Wang, Wei W; Zhang, Yang Z
> Subject: [PATCH] KVM: x86: keep EOI exit bitmap accurate before loading it.
> 
> Guest may mask the IOAPIC entry before issue EOI. In such case, EOI will not be intercepted by hypervisor, since the corrensponding bit in eoi exit bitmap is not set after the masking of IOAPIC entry.
> 
> The solution here is to OR EOI_exit_bitmap with tmr.
> 
> Tested-by: Rongrong Liu <rongrongx.liu@intel.com>
> Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>
> Signed-off-by: Wei Wang <wei.w.wang@intel.com>
> ---
>  arch/x86/kvm/lapic.c |    9 +++++++++
>  arch/x86/kvm/lapic.h |    2 ++
>  arch/x86/kvm/x86.c   |    1 +
>  virt/kvm/ioapic.c    |    6 +++---
>  4 files changed, 15 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 93c2e93..759d24e 100644
> --- a/arch/x86/kvm/lapic.c
> +++ b/arch/x86/kvm/lapic.c
> @@ -533,6 +533,15 @@ void kvm_apic_update_tmr(struct kvm_vcpu *vcpu, u32 *tmr)
>  	}
>  }
>  
> +void kvm_apic_update_eoi_exitmap(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap,
> +					u32 *tmr)
> +{
> +	u32 i;
> +
> +	for (i = 0; i < 8; i++)
> +		*((u32 *)eoi_exit_bitmap + i) |= tmr[i]; }
> +
>  static void apic_update_ppr(struct kvm_lapic *apic)  {
>  	u32 tpr, isrv, ppr, old_ppr;
> diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h index 6a11845..eda7be7 100644
> --- a/arch/x86/kvm/lapic.h
> +++ b/arch/x86/kvm/lapic.h
> @@ -55,6 +55,8 @@ void kvm_apic_set_version(struct kvm_vcpu *vcpu);
>  
>  void kvm_apic_update_tmr(struct kvm_vcpu *vcpu, u32 *tmr);  void kvm_apic_update_irr(struct kvm_vcpu *vcpu, u32 *pir);
> +void kvm_apic_update_eoi_exitmap(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap,
> +					u32 *tmr);
>  int kvm_apic_match_physical_addr(struct kvm_lapic *apic, u16 dest);  int kvm_apic_match_logical_addr(struct kvm_lapic *apic, u8 mda);  int kvm_apic_set_irq(struct kvm_vcpu *vcpu, struct kvm_lapic_irq *irq, diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index d401684..4042bc0 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -5992,6 +5992,7 @@ static void vcpu_scan_ioapic(struct kvm_vcpu *vcpu)
>  
>  	kvm_ioapic_scan_entry(vcpu, eoi_exit_bitmap, tmr);
>  	kvm_apic_update_tmr(vcpu, tmr);
> +	kvm_apic_update_eoi_exitmap(vcpu, eoi_exit_bitmap, tmr);
>  	kvm_x86_ops->load_eoi_exitmap(vcpu, eoi_exit_bitmap);  }
>  
> diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c index e8ce34c..ea5f697 100644
> --- a/virt/kvm/ioapic.c
> +++ b/virt/kvm/ioapic.c
> @@ -254,9 +254,9 @@ void kvm_ioapic_scan_entry(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap,
>  	spin_lock(&ioapic->lock);
>  	for (index = 0; index < IOAPIC_NUM_PINS; index++) {
>  		e = &ioapic->redirtbl[index];
> -		if (e->fields.trig_mode == IOAPIC_LEVEL_TRIG ||
> -		    kvm_irq_has_notifier(ioapic->kvm, KVM_IRQCHIP_IOAPIC, index) ||
> -		    index == RTC_GSI) {
> +		if (!e->fields.mask && e->fields.trig_mode == IOAPIC_LEVEL_TRIG
> +			|| kvm_irq_has_notifier(ioapic->kvm, KVM_IRQCHIP_IOAPIC,
> +				index) || index == RTC_GSI) {
>  			if (kvm_apic_match_dest(vcpu, NULL, 0,
>  				e->fields.dest_id, e->fields.dest_mode)) {
>  				__set_bit(e->fields.vector,
> --
> 1.7.1
> 



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Paolo Bonzini Aug. 27, 2014, 6:55 a.m. UTC | #2 
Il 26/08/2014 23:01, Alex Williamson ha scritto:
>> > Hi Alex,
>> > Could you have a test if the two patches have solved the bug?
> What case was missed by the previous single patch that is accounted for
> now

None, I asked to split the patch into TMR cleanup and actual bugfix. :)

Though I agree that the patches are lacking comments.

Paolo

> Some sort of comment in the update_tmr function would be nice to
> explain the update, along with removing the unnecessary arrays as Paolo
> pointed out, and I commented on in the previous version.  Thanks,

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diff mbox

Patch

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 93c2e93..759d24e 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -533,6 +533,15 @@  void kvm_apic_update_tmr(struct kvm_vcpu *vcpu, u32 *tmr)
 	}
 }
 
+void kvm_apic_update_eoi_exitmap(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap,
+					u32 *tmr)
+{
+	u32 i;
+
+	for (i = 0; i < 8; i++)
+		*((u32 *)eoi_exit_bitmap + i) |= tmr[i]; }
+
 static void apic_update_ppr(struct kvm_lapic *apic)  {
 	u32 tpr, isrv, ppr, old_ppr;
diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h index 6a11845..eda7be7 100644
--- a/arch/x86/kvm/lapic.h
+++ b/arch/x86/kvm/lapic.h
@@ -55,6 +55,8 @@  void kvm_apic_set_version(struct kvm_vcpu *vcpu);
 
 void kvm_apic_update_tmr(struct kvm_vcpu *vcpu, u32 *tmr);  void kvm_apic_update_irr(struct kvm_vcpu *vcpu, u32 *pir);
+void kvm_apic_update_eoi_exitmap(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap,
+					u32 *tmr);
 int kvm_apic_match_physical_addr(struct kvm_lapic *apic, u16 dest);  int kvm_apic_match_logical_addr(struct kvm_lapic *apic, u8 mda);  int kvm_apic_set_irq(struct kvm_vcpu *vcpu, struct kvm_lapic_irq *irq, diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index d401684..4042bc0 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5992,6 +5992,7 @@  static void vcpu_scan_ioapic(struct kvm_vcpu *vcpu)
 
 	kvm_ioapic_scan_entry(vcpu, eoi_exit_bitmap, tmr);
 	kvm_apic_update_tmr(vcpu, tmr);
+	kvm_apic_update_eoi_exitmap(vcpu, eoi_exit_bitmap, tmr);
 	kvm_x86_ops->load_eoi_exitmap(vcpu, eoi_exit_bitmap);  }
 
diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c index e8ce34c..ea5f697 100644
--- a/virt/kvm/ioapic.c
+++ b/virt/kvm/ioapic.c
@@ -254,9 +254,9 @@  void kvm_ioapic_scan_entry(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap,
 	spin_lock(&ioapic->lock);
 	for (index = 0; index < IOAPIC_NUM_PINS; index++) {
 		e = &ioapic->redirtbl[index];
-		if (e->fields.trig_mode == IOAPIC_LEVEL_TRIG ||
-		    kvm_irq_has_notifier(ioapic->kvm, KVM_IRQCHIP_IOAPIC, index) ||
-		    index == RTC_GSI) {
+		if (!e->fields.mask && e->fields.trig_mode == IOAPIC_LEVEL_TRIG
+			|| kvm_irq_has_notifier(ioapic->kvm, KVM_IRQCHIP_IOAPIC,
+				index) || index == RTC_GSI) {
 			if (kvm_apic_match_dest(vcpu, NULL, 0,
 				e->fields.dest_id, e->fields.dest_mode)) {
 				__set_bit(e->fields.vector,