[PATCH] kvm: bypass irq_pending get/set when using in kernel irqchip

[PATCH] kvm: bypass irq_pending get/set when using in kernel irqchip

[He, Qing]

[-- Attachment #1: Type: text/plain, Size: 1723 bytes --]

vcpu->irq_pending is saved in get/set_sreg IOCTL, but when in-kernel
local APIC is used, doing this may occasionally overwrite vcpu->apic to
an invalid value, as in the vm restore path.

Signed-off-by: Qing He <qing.he-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>

----
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index dae8540..9472e7f 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -2141,8 +2141,12 @@ static int kvm_vcpu_ioctl_get_sregs(struct
kvm_vcpu *vcpu,
 	sregs->efer = vcpu->shadow_efer;
 	sregs->apic_base = kvm_get_apic_base(vcpu);
 
-	memcpy(sregs->interrupt_bitmap, vcpu->irq_pending,
-	       sizeof sregs->interrupt_bitmap);
+	if (irqchip_in_kernel(vcpu->kvm))
+		memset(sregs->interrupt_bitmap, 0,
+		       sizeof sregs->interrupt_bitmap);
+	else
+		memcpy(sregs->interrupt_bitmap, vcpu->irq_pending,
+		       sizeof sregs->interrupt_bitmap);
 
 	vcpu_put(vcpu);
 
@@ -2196,12 +2200,14 @@ static int kvm_vcpu_ioctl_set_sregs(struct
kvm_vcpu *vcpu,
 	if (mmu_reset_needed)
 		kvm_mmu_reset_context(vcpu);
 
-	memcpy(vcpu->irq_pending, sregs->interrupt_bitmap,
-	       sizeof vcpu->irq_pending);
-	vcpu->irq_summary = 0;
-	for (i = 0; i < ARRAY_SIZE(vcpu->irq_pending); ++i)
-		if (vcpu->irq_pending[i])
-			__set_bit(i, &vcpu->irq_summary);
+	if (!irqchip_in_kernel(vcpu->kvm)) {
+		memcpy(vcpu->irq_pending, sregs->interrupt_bitmap,
+		       sizeof vcpu->irq_pending);
+		vcpu->irq_summary = 0;
+		for (i = 0; i < ARRAY_SIZE(vcpu->irq_pending); ++i)
+			if (vcpu->irq_pending[i])
+				__set_bit(i, &vcpu->irq_summary);
+	}
 
 	set_segment(vcpu, &sregs->cs, VCPU_SREG_CS);
 	set_segment(vcpu, &sregs->ds, VCPU_SREG_DS);

[-- Attachment #2: apic-lm-prepatch-kern-alt.diff --]
[-- Type: application/octet-stream, Size: 1408 bytes --]

diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index dae8540..9472e7f 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -2141,8 +2141,12 @@ static int kvm_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
 	sregs->efer = vcpu->shadow_efer;
 	sregs->apic_base = kvm_get_apic_base(vcpu);
 
-	memcpy(sregs->interrupt_bitmap, vcpu->irq_pending,
-	       sizeof sregs->interrupt_bitmap);
+	if (irqchip_in_kernel(vcpu->kvm))
+		memset(sregs->interrupt_bitmap, 0,
+		       sizeof sregs->interrupt_bitmap);
+	else
+		memcpy(sregs->interrupt_bitmap, vcpu->irq_pending,
+		       sizeof sregs->interrupt_bitmap);
 
 	vcpu_put(vcpu);
 
@@ -2196,12 +2200,14 @@ static int kvm_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
 	if (mmu_reset_needed)
 		kvm_mmu_reset_context(vcpu);
 
-	memcpy(vcpu->irq_pending, sregs->interrupt_bitmap,
-	       sizeof vcpu->irq_pending);
-	vcpu->irq_summary = 0;
-	for (i = 0; i < ARRAY_SIZE(vcpu->irq_pending); ++i)
-		if (vcpu->irq_pending[i])
-			__set_bit(i, &vcpu->irq_summary);
+	if (!irqchip_in_kernel(vcpu->kvm)) {
+		memcpy(vcpu->irq_pending, sregs->interrupt_bitmap,
+		       sizeof vcpu->irq_pending);
+		vcpu->irq_summary = 0;
+		for (i = 0; i < ARRAY_SIZE(vcpu->irq_pending); ++i)
+			if (vcpu->irq_pending[i])
+				__set_bit(i, &vcpu->irq_summary);
+	}
 
 	set_segment(vcpu, &sregs->cs, VCPU_SREG_CS);
 	set_segment(vcpu, &sregs->ds, VCPU_SREG_DS);

[-- Attachment #3: Type: text/plain, Size: 315 bytes --]

-------------------------------------------------------------------------
This SF.net email is sponsored by: Splunk Inc.
Still grepping through log files to find problems?  Stop.
Now Search log events and configuration files using AJAX and a browser.
Download your FREE copy of Splunk now >>  http://get.splunk.com/

[-- Attachment #4: Type: text/plain, Size: 186 bytes --]

_______________________________________________
kvm-devel mailing list
kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org
https://lists.sourceforge.net/lists/listinfo/kvm-devel

Re: [PATCH] kvm: bypass irq_pending get/set when using in kernel irqchip

[Avi Kivity]

He, Qing wrote:
> vcpu->irq_pending is saved in get/set_sreg IOCTL, but when in-kernel
> local APIC is used, doing this may occasionally overwrite vcpu->apic to
> an invalid value, as in the vm restore path.
>
>   

Applied, thanks.

-- 
error compiling committee.c: too many arguments to function


-------------------------------------------------------------------------
This SF.net email is sponsored by: Splunk Inc.
Still grepping through log files to find problems?  Stop.
Now Search log events and configuration files using AJAX and a browser.
Download your FREE copy of Splunk now >>  http://get.splunk.com/