[PATCH 071/104] KVM: Bypass irq_pending get/set when using in kernel irqchip

Avi Kivity
2007-09-17T08:45:27Z

From: He, Qing <qing.he@intel.com>

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@intel.com>
---
drivers/kvm/kvm_main.c | 22 ++++++++++++++--------
1 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 6e2c5f3..c270e4a 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -2145,8 +2145,12 @@ 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);

@@ -2200,12 +2204,14 @@ 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);
--
1.5.3