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From: Vitaly Kuznetsov <vkuznets@redhat.com>
To: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org,
	"Paolo Bonzini" <pbonzini@redhat.com>,
	"Radim Krčmář" <rkrcmar@redhat.com>,
	"Joerg Roedel" <joro@8bytes.org>,
	"Jim Mattson" <jmattson@google.com>
Subject: [PATCH 2/5] x86: KVM: svm: avoid flooding logs when skip_emulated_instruction() fails
Date: Thu,  1 Aug 2019 07:14:15 +0200	[thread overview]
Message-ID: <20190801051418.15905-3-vkuznets@redhat.com> (raw)
In-Reply-To: <20190801051418.15905-1-vkuznets@redhat.com>

When we're unable to skip instruction with kvm_emulate_instruction() we
will not advance RIP and most likely the guest will get stuck as
consequitive attempts to execute the same instruction will likely result
in the same behavior.

As we're not supposed to see these messages under normal conditions, switch
to pr_err_once().

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
---
 arch/x86/kvm/svm.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 7e843b340490..80f576e05112 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -782,7 +782,8 @@ static void skip_emulated_instruction(struct kvm_vcpu *vcpu)
 	if (!svm->next_rip) {
 		if (kvm_emulate_instruction(vcpu, EMULTYPE_SKIP) !=
 				EMULATE_DONE)
-			printk(KERN_DEBUG "%s: NOP\n", __func__);
+			pr_err_once("KVM: %s: unable to skip instruction\n",
+				    __func__);
 		return;
 	}
 	if (svm->next_rip - kvm_rip_read(vcpu) > MAX_INST_SIZE)
-- 
2.20.1


  parent reply	other threads:[~2019-08-01  5:14 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-01  5:14 [PATCH 0/5] x86: KVM: svm: get rid of hardcoded instructions lengths Vitaly Kuznetsov
2019-08-01  5:14 ` [PATCH 1/5] x86: KVM: svm: don't pretend to advance RIP in case wrmsr_interception() results in #GP Vitaly Kuznetsov
2019-08-01  5:14 ` Vitaly Kuznetsov [this message]
2019-08-01  5:14 ` [PATCH 3/5] x86: KVM: svm: clear interrupt shadow on all paths in skip_emulated_instruction() Vitaly Kuznetsov
2019-08-01 14:18   ` Sean Christopherson
2019-08-01 14:43     ` Vitaly Kuznetsov
2019-08-01  5:14 ` [PATCH 4/5] x86: KVM: add xsetbv to the emulator Vitaly Kuznetsov
2019-08-01  5:14 ` [PATCH 5/5] x86: KVM: svm: remove hardcoded instruction length from intercepts Vitaly Kuznetsov

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