lkml.org 
[lkml]   [2021]   [Apr]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2 3/3] KVM: X86: Do not yield to self
Date
From: Wanpeng Li <wanpengli@tencent.com>

If the target is self we do not need to yield, we can avoid malicious
guest to play this.

Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
---
v1 -> v2:
* update comments

arch/x86/kvm/x86.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index f08e9b4..ce9a1d2 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -8231,6 +8231,10 @@ static void kvm_sched_yield(struct kvm_vcpu *vcpu, unsigned long dest_id)
if (!target || !READ_ONCE(target->ready))
goto no_yield;

+ /* Ignore requests to yield to self */
+ if (vcpu == target)
+ goto no_yield;
+
if (kvm_vcpu_yield_to(target) <= 0)
goto no_yield;

--
2.7.4
\
 
 \ /
  Last update: 2021-04-09 06:20    [W:0.121 / U:0.628 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site