Re: [PATCH v5 12/12] Send async PF when guest is not in userspacetoo.

From: Avi Kivity
Date: Tue Aug 24 2010 - 05:37:15 EST


On 07/19/2010 06:31 PM, Gleb Natapov wrote:
If guest indicates that it can handle async pf in kernel mode too send
it, but only if interrupt are enabled.

Reviewed-by: Rik van Riel<riel@xxxxxxxxxx>
Signed-off-by: Gleb Natapov<gleb@xxxxxxxxxx>
---
arch/x86/kvm/mmu.c | 8 +++++++-
1 files changed, 7 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 12d1a7b..ed87b1c 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2361,7 +2361,13 @@ static bool can_do_async_pf(struct kvm_vcpu *vcpu)
if (!vcpu->arch.apf_data || kvm_event_needs_reinjection(vcpu))
return false;

- return !!kvm_x86_ops->get_cpl(vcpu);
+ if (vcpu->arch.apf_send_user_only)
+ return !!kvm_x86_ops->get_cpl(vcpu);

cpl is not a bool. Compare it with 0.

+
+ if (!kvm_x86_ops->interrupt_allowed(vcpu))
+ return false;
+
+ return true;
}

Should have commented before, but get_cpl() is not accurate when doing nested virtualization. When L1 intercepts page faults, being in L2 is equivalent to CPL 3. But we need to get the apf information to L1 somehow.

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

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