From: Maxim Levitsky <mlevitsk@redhat.com>
To: kvm@vger.kernel.org
Cc: Ingo Molnar <mingo@redhat.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Sean Christopherson <seanjc@google.com>,
Borislav Petkov <bp@alien8.de>, "H. Peter Anvin" <hpa@zytor.com>,
Thomas Gleixner <tglx@linutronix.de>,
Jim Mattson <jmattson@google.com>,
x86@kernel.org, Vitaly Kuznetsov <vkuznets@redhat.com>,
Joerg Roedel <joro@8bytes.org>,
linux-kernel@vger.kernel.org, Paolo Bonzini <pbonzini@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Maxim Levitsky <mlevitsk@redhat.com>
Subject: [PATCH v3 6/7] KVM: x86: SVM: allow to force AVIC to be enabled
Date: Tue, 1 Mar 2022 16:36:49 +0200 [thread overview]
Message-ID: <20220301143650.143749-7-mlevitsk@redhat.com> (raw)
In-Reply-To: <20220301143650.143749-1-mlevitsk@redhat.com>
Apparently on some systems AVIC is disabled in CPUID but still usable.
Allow the user to override the CPUID if the user is willing to
take the risk.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
---
arch/x86/kvm/svm/svm.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 776585dd77769..a26b4c899899e 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -202,6 +202,9 @@ module_param(tsc_scaling, int, 0444);
static bool avic;
module_param(avic, bool, 0444);
+static bool force_avic;
+module_param_unsafe(force_avic, bool, 0444);
+
bool __read_mostly dump_invalid_vmcb;
module_param(dump_invalid_vmcb, bool, 0644);
@@ -4896,10 +4899,14 @@ static __init int svm_hardware_setup(void)
nrips = false;
}
- enable_apicv = avic = avic && npt_enabled && boot_cpu_has(X86_FEATURE_AVIC);
+ enable_apicv = avic = avic && npt_enabled && (boot_cpu_has(X86_FEATURE_AVIC) || force_avic);
if (enable_apicv) {
- pr_info("AVIC enabled\n");
+ if (!boot_cpu_has(X86_FEATURE_AVIC)) {
+ pr_warn("AVIC is not supported in CPUID but force enabled");
+ pr_warn("Your system might crash and burn");
+ } else
+ pr_info("AVIC enabled\n");
amd_iommu_register_ga_log_notifier(&avic_ga_log_notifier);
} else {
--
2.26.3
next prev parent reply other threads:[~2022-03-01 14:38 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-01 14:36 [PATCH v3 0/7] nSVM/SVM features Maxim Levitsky
2022-03-01 14:36 ` [PATCH v3 1/7] KVM: x86: nSVM: correctly virtualize LBR msrs when L2 is running Maxim Levitsky
2022-03-09 13:00 ` Paolo Bonzini
2022-03-14 11:25 ` Maxim Levitsky
2022-03-01 14:36 ` [PATCH v3 2/7] KVM: x86: nSVM: implement nested LBR virtualization Maxim Levitsky
2022-03-09 13:00 ` Paolo Bonzini
2022-03-22 16:53 ` Maxim Levitsky
2022-03-01 14:36 ` [PATCH v3 3/7] KVM: x86: nSVM: implement nested VMLOAD/VMSAVE Maxim Levitsky
2022-03-01 14:36 ` [PATCH v3 4/7] KVM: x86: nSVM: support PAUSE filter threshold and count when cpu_pm=on Maxim Levitsky
2022-03-09 13:12 ` Paolo Bonzini
2022-03-22 16:52 ` Maxim Levitsky
2022-03-09 18:35 ` Jim Mattson
2022-03-09 18:47 ` Paolo Bonzini
2022-03-09 19:07 ` Jim Mattson
2022-03-21 21:36 ` Maxim Levitsky
2022-03-21 21:59 ` Jim Mattson
2022-03-21 22:11 ` Maxim Levitsky
2022-03-21 22:41 ` Jim Mattson
2022-03-22 10:12 ` Paolo Bonzini
2022-03-22 11:17 ` Maxim Levitsky
2022-03-01 14:36 ` [PATCH v3 5/7] KVM: x86: nSVM: implement nested vGIF Maxim Levitsky
2022-03-09 13:40 ` Paolo Bonzini
2022-03-14 15:21 ` Maxim Levitsky
2022-03-01 14:36 ` Maxim Levitsky [this message]
2022-03-09 13:41 ` [PATCH v3 6/7] KVM: x86: SVM: allow to force AVIC to be enabled Paolo Bonzini
2022-03-01 14:36 ` [PATCH v3 7/7] KVM: x86: SVM: allow AVIC to co-exist with a nested guest running Maxim Levitsky
2022-03-09 13:50 ` Paolo Bonzini
2022-03-09 18:14 ` Maxim Levitsky
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20220301143650.143749-7-mlevitsk@redhat.com \
--to=mlevitsk@redhat.com \
--cc=bp@alien8.de \
--cc=dave.hansen@linux.intel.com \
--cc=hpa@zytor.com \
--cc=jmattson@google.com \
--cc=joro@8bytes.org \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=pbonzini@redhat.com \
--cc=seanjc@google.com \
--cc=tglx@linutronix.de \
--cc=vkuznets@redhat.com \
--cc=wanpengli@tencent.com \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).