From: Vineeth Pillai <viremana@linux.microsoft.com>
To: Vitaly Kuznetsov <vkuznets@redhat.com>,
Paolo Bonzini <pbonzini@redhat.com>,
kvm@vger.kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
"K. Y. Srinivasan" <kys@microsoft.com>,
x86@kernel.org, linux-kernel@vger.kernel.org,
linux-hyperv@vger.kernel.org,
Lan Tianyu <Tianyu.Lan@microsoft.com>,
Michael Kelley <mikelley@microsoft.com>,
Sean Christopherson <seanjc@google.com>,
Tom Lendacky <thomas.lendacky@amd.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
Wei Liu <wei.liu@kernel.org>,
Stephen Hemminger <sthemmin@microsoft.com>,
Haiyang Zhang <haiyangz@microsoft.com>,
Maxim Levitsky <mlevitsk@redhat.com>
Subject: Re: [PATCH v5 7/7] KVM: SVM: hyper-v: Direct Virtual Flush support
Date: Tue, 15 Jun 2021 10:24:14 -0400 [thread overview]
Message-ID: <73508c14-3ca6-1d20-8f9e-14bd966c849a@linux.microsoft.com> (raw)
In-Reply-To: <878s3c65nr.fsf@vitty.brq.redhat.com>
Hi Vitaly,
>> +
>> +static inline void svm_hv_update_vp_id(struct vmcb *vmcb,
>> + struct kvm_vcpu *vcpu)
>> +{
>> + struct hv_enlightenments *hve =
>> + (struct hv_enlightenments *)vmcb->control.reserved_sw;
>> +
>> + if (hve->hv_vp_id != to_hv_vcpu(vcpu)->vp_index) {
>> + hve->hv_vp_id = to_hv_vcpu(vcpu)->vp_index;
>> + vmcb_mark_dirty(vmcb, VMCB_HV_NESTED_ENLIGHTENMENTS);
>> + }
> This blows up in testing when no Hyper-V context was created on a vCPU,
> e.g. when running KVM selftests (to_hv_vcpu(vcpu) is NULL when no
> Hyper-V emulation features were requested on a vCPU but
> svm_hv_update_vp_id() is called unconditionally by svm_vcpu_run()).
>
> I'll be sending a patch to fix the immediate issue but I was wondering
> why we need to call svm_hv_update_vp_id() from svm_vcpu_run() as VP
> index is unlikely to change; we can probably just call it from
> kvm_hv_set_msr() instead.
Thanks a lot for catching this.
I think you are right, updating at kvm_hv_set_msr() makes sense. I was
following the vmx logic where it also sets the vp_id in vmx_vcpu_run. But it
calls a wrapper "kvm_hv_get_vpindex" which actually checks if hv_vcpu is not
null before the assignment. I should have used that instead, my mistake.
I will look a bit more into it and send out a patch for vmx and svm
after little
more investigation.
Thanks,
Vineeth
next prev parent reply other threads:[~2021-06-15 14:25 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-03 15:14 [PATCH v5 0/7] Hyper-V nested virt enlightenments for SVM Vineeth Pillai
2021-06-03 15:14 ` [PATCH v5 1/7] hyperv: Detect Nested virtualization support " Vineeth Pillai
2021-06-08 16:59 ` Michael Kelley
2021-06-03 15:14 ` [PATCH v5 2/7] hyperv: SVM enlightened TLB flush support flag Vineeth Pillai
2021-06-08 17:04 ` Michael Kelley
2021-06-03 15:14 ` [PATCH v5 3/7] KVM: x86: hyper-v: Move the remote TLB flush logic out of vmx Vineeth Pillai
2021-06-10 11:20 ` Vitaly Kuznetsov
2021-06-10 15:11 ` Paolo Bonzini
2021-06-11 7:20 ` Vitaly Kuznetsov
2021-06-03 15:14 ` [PATCH v5 4/7] KVM: SVM: Software reserved fields Vineeth Pillai
2021-06-03 15:14 ` [PATCH v5 5/7] KVM: SVM: hyper-v: Remote TLB flush for SVM Vineeth Pillai
2021-06-08 17:33 ` Michael Kelley
2021-06-03 15:14 ` [PATCH v5 6/7] KVM: SVM: hyper-v: Enlightened MSR-Bitmap support Vineeth Pillai
2021-06-03 15:14 ` [PATCH v5 7/7] KVM: SVM: hyper-v: Direct Virtual Flush support Vineeth Pillai
2021-06-10 11:16 ` Vitaly Kuznetsov
2021-06-10 15:16 ` Paolo Bonzini
2021-06-14 11:34 ` Vitaly Kuznetsov
2021-06-15 14:24 ` Vineeth Pillai [this message]
2021-06-10 15:17 ` [PATCH v5 0/7] Hyper-V nested virt enlightenments for SVM Paolo Bonzini
2021-06-11 9:26 ` Maxim Levitsky
2021-06-11 9:44 ` Vitaly Kuznetsov
2021-06-11 16:50 ` Paolo Bonzini
2021-06-14 7:47 ` Vitaly Kuznetsov
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=73508c14-3ca6-1d20-8f9e-14bd966c849a@linux.microsoft.com \
--to=viremana@linux.microsoft.com \
--cc=Tianyu.Lan@microsoft.com \
--cc=bp@alien8.de \
--cc=haiyangz@microsoft.com \
--cc=hpa@zytor.com \
--cc=jmattson@google.com \
--cc=joro@8bytes.org \
--cc=kvm@vger.kernel.org \
--cc=kys@microsoft.com \
--cc=linux-hyperv@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mikelley@microsoft.com \
--cc=mingo@redhat.com \
--cc=mlevitsk@redhat.com \
--cc=pbonzini@redhat.com \
--cc=seanjc@google.com \
--cc=sthemmin@microsoft.com \
--cc=tglx@linutronix.de \
--cc=thomas.lendacky@amd.com \
--cc=vkuznets@redhat.com \
--cc=wanpengli@tencent.com \
--cc=wei.liu@kernel.org \
--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).