From: Sean Christopherson <sean.j.christopherson@intel.com>
To: Maxim Levitsky <mlevitsk@redhat.com>
Cc: kvm@vger.kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Joerg Roedel <joro@8bytes.org>,
Paolo Bonzini <pbonzini@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Thomas Gleixner <tglx@linutronix.de>,
linux-kernel@vger.kernel.org, Jim Mattson <jmattson@google.com>,
"maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)"
<x86@kernel.org>
Subject: Re: [PATCH v6 4/4] KVM: nSVM: implement on demand allocation of the nested state
Date: Mon, 28 Sep 2020 22:15:26 -0700 [thread overview]
Message-ID: <20200929051526.GD353@linux.intel.com> (raw)
In-Reply-To: <20200922211025.175547-5-mlevitsk@redhat.com>
On Wed, Sep 23, 2020 at 12:10:25AM +0300, Maxim Levitsky wrote:
> This way we don't waste memory on VMs which don't use nesting
> virtualization even when the host enabled it for them.
>
> Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
> ---
> arch/x86/kvm/svm/nested.c | 42 ++++++++++++++++++++++++++++++
> arch/x86/kvm/svm/svm.c | 55 ++++++++++++++++++++++-----------------
> arch/x86/kvm/svm/svm.h | 6 +++++
> 3 files changed, 79 insertions(+), 24 deletions(-)
>
> diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
> index 09417f5197410..dd13856818a03 100644
> --- a/arch/x86/kvm/svm/nested.c
> +++ b/arch/x86/kvm/svm/nested.c
> @@ -467,6 +467,9 @@ int nested_svm_vmrun(struct vcpu_svm *svm)
>
> vmcb12 = map.hva;
>
> + if (WARN_ON(!svm->nested.initialized))
Probably should use WARN_ON_ONCE, if this is somehow it, userspace could
easily spam the kernel.
Side topic, do we actually need 'initialized'? Wouldn't checking for a
valid nested.msrpm or nested.hsave suffice?
> + return 1;
> +
> if (!nested_vmcb_checks(svm, vmcb12)) {
> vmcb12->control.exit_code = SVM_EXIT_ERR;
> vmcb12->control.exit_code_hi = 0;
> @@ -684,6 +687,45 @@ int nested_svm_vmexit(struct vcpu_svm *svm)
> return 0;
> }
next prev parent reply other threads:[~2020-09-29 5:15 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-22 21:10 [PATCH v6 0/4] KVM: nSVM: ondemand nested state allocation Maxim Levitsky
2020-09-22 21:10 ` [PATCH v6 1/4] KVM: x86: xen_hvm_config: cleanup return values Maxim Levitsky
2020-09-22 21:10 ` [PATCH v6 2/4] KVM: x86: report negative values from wrmsr emulation to userspace Maxim Levitsky
2020-10-26 19:40 ` Qian Cai
2020-10-27 20:31 ` Qian Cai
2020-10-28 8:51 ` Maxim Levitsky
2020-09-22 21:10 ` [PATCH v6 3/4] KVM: x86: allow kvm_x86_ops.set_efer to return an error value Maxim Levitsky
2020-09-29 5:12 ` Sean Christopherson
2020-09-22 21:10 ` [PATCH v6 4/4] KVM: nSVM: implement on demand allocation of the nested state Maxim Levitsky
2020-09-29 5:15 ` Sean Christopherson [this message]
2020-09-30 15:35 ` Maxim Levitsky
2020-10-01 0:26 ` Sean Christopherson
2020-09-30 15:36 ` [PATCH v6 0/4] KVM: nSVM: ondemand nested state allocation 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=20200929051526.GD353@linux.intel.com \
--to=sean.j.christopherson@intel.com \
--cc=bp@alien8.de \
--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=mlevitsk@redhat.com \
--cc=pbonzini@redhat.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).