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

[He, Qing]

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 <[EMAIL PROTECTED]>

----
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);

apic-lm-prepatch-kern-alt.diff
Description: apic-lm-prepatch-kern-alt.diff

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