KVM: fix hypercall cache/decache

PATCH In review Ingo Molnar 2 participants 3 messages Mar 20, 2007 2 messages not in the archive KVM

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Ingo Molnar

author

2007-03-20 08:54 UTC #0 lore raw

PATCH 1/1 KVM: fix hypercall cache/decache

Subject: [patch] KVM: fix hypercall cache/decache
From: Ingo Molnar <[email protected]>

a recent change to kvm_hypercall() flipped around the order of ->cache_regs() and ->decache_regs(), but that is bogus and causes ESP/RIP corruption: ->cache_regs() will 'cache' the CPU-side registers into the vcpu structure, and ->decache_regs() will sync it back to the CPU.

fix this by using the correct order again.

Signed-off-by Ingo Molnar <[email protected]>

---
 drivers/kvm/kvm_main.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

drivers/kvm/kvm_main.c +3 -2

Index: linux/drivers/kvm/kvm_main.c
===================================================================
@@ -1177,7 +1177,7 @@ int kvm_hypercall(struct kvm_vcpu *vcpu,
 {
 	unsigned long nr, a0, a1, a2, a3, a4, a5, ret;
 
-	kvm_arch_ops->decache_regs(vcpu);
+	kvm_arch_ops->cache_regs(vcpu);
 	ret = -KVM_EINVAL;
 #ifdef CONFIG_X86_64
 	if (is_long_mode(vcpu)) {

@@ -1204,7 +1204,8 @@ int kvm_hypercall(struct kvm_vcpu *vcpu,
 		;
 	}
 	vcpu->regs[VCPU_REGS_RAX] = ret;
-	kvm_arch_ops->cache_regs(vcpu);
+	kvm_arch_ops->decache_regs(vcpu);
+
 	return 1;
 }
 EXPORT_SYMBOL_GPL(kvm_hypercall);

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A message that is not in the archive (sent off-list or not yet received): [email protected]

Avi Kivity

2007-03-20 09:21 UTC #2 lore raw

Quoted 12 lines · Ingo Molnar

Subject: [patch] KVM: fix hypercall cache/decache
From: Ingo Molnar <[email protected]>
a recent change to kvm_hypercall() flipped around the order of ->cache_regs() and ->decache_regs(), but that is bogus and causes ESP/RIP corruption: ->cache_regs() will 'cache' the CPU-side registers into the vcpu structure, and ->decache_regs() will sync it back to the CPU.
fix this by using the correct order again.

That's 57d78025d84fb607aa335d015a79b257517aa209 in my tree...

Signature · 8 lines

error compiling committee.c: too many arguments to function


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A message that is not in the archive (sent off-list or not yet received): 45FFA790.7080007-atKUWr5tajBWk0Htik3J/[email protected]

Ingo Molnar

author

2007-03-20 09:25 UTC #4 lore raw

Quoted 10 lines · Avi Kivity

Quoted 9 lines · Ingo Molnar
Subject: [patch] KVM: fix hypercall cache/decache
From: Ingo Molnar <[email protected]>
a recent change to kvm_hypercall() flipped around the order of ->cache_regs() and ->decache_regs(), but that is bogus and causes ESP/RIP corruption: ->cache_regs() will 'cache' the CPU-side registers into the vcpu structure, and ->decache_regs() will sync it back to the CPU.

Quoted 3 lines

Quoted 1 line
fix this by using the correct order again.
That's 57d78025d84fb607aa335d015a79b257517aa209 in my tree...

ok :)

Ingo