From: Sean Christopherson <sean.j.christopherson@intel.com>
To: Alexander Graf <graf@amazon.com>
Cc: Aaron Lewis <aaronlewis@google.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Jonathan Corbet <corbet@lwn.net>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
KarimAllah Raslan <karahmed@amazon.de>,
Dan Carpenter <dan.carpenter@oracle.com>,
kvm list <kvm@vger.kernel.org>,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v6 1/7] KVM: x86: Deflect unknown MSR accesses to user space
Date: Wed, 16 Sep 2020 10:08:39 -0700 [thread overview]
Message-ID: <20200916170839.GD10227@sjchrist-ice> (raw)
In-Reply-To: <186ccace-2fad-3db3-0848-cd272b1a64ba@amazon.com>
On Wed, Sep 16, 2020 at 11:31:30AM +0200, Alexander Graf wrote:
> On 03.09.20 21:27, Aaron Lewis wrote:
> > > @@ -412,6 +414,15 @@ struct kvm_run {
> > > __u64 esr_iss;
> > > __u64 fault_ipa;
> > > } arm_nisv;
> > > + /* KVM_EXIT_X86_RDMSR / KVM_EXIT_X86_WRMSR */
> > > + struct {
> > > + __u8 error; /* user -> kernel */
> > > + __u8 pad[3];
> >
> > __u8 pad[7] to maintain 8 byte alignment? unless we can get away with
> > fewer bits for 'reason' and
> > get them from 'pad'.
>
> Why would we need an 8 byte alignment here? I always thought natural u64
> alignment on x86_64 was on 4 bytes?
u64 will usually (always?) be 8 byte aligned by the compiler. "Natural"
alignment means an object is aligned to its size. E.g. an 8-byte object
can split a cache line if it's only aligned on a 4-byte boundary.
next prev parent reply other threads:[~2020-09-16 20:37 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-02 12:59 [PATCH v6 0/7] Allow user space to restrict and augment MSR emulation Alexander Graf
2020-09-02 12:59 ` [PATCH v6 1/7] KVM: x86: Deflect unknown MSR accesses to user space Alexander Graf
2020-09-03 19:27 ` Aaron Lewis
2020-09-16 9:31 ` Alexander Graf
2020-09-16 17:08 ` Sean Christopherson [this message]
2020-09-16 19:15 ` Alexander Graf
2020-09-17 19:38 ` Aaron Lewis
2020-09-02 12:59 ` [PATCH v6 2/7] KVM: x86: Add infrastructure for MSR filtering Alexander Graf
2020-09-02 12:59 ` [PATCH v6 3/7] KVM: x86: Prepare MSR bitmaps for userspace tracked MSRs Alexander Graf
2020-09-02 12:59 ` [PATCH v6 4/7] KVM: x86: SVM: Prevent MSR passthrough when MSR access is denied Alexander Graf
2020-09-02 12:59 ` [PATCH v6 5/7] KVM: x86: VMX: " Alexander Graf
2020-09-04 2:18 ` Aaron Lewis
2020-09-16 19:44 ` Alexander Graf
2020-09-16 20:13 ` Aaron Lewis
2020-09-16 20:36 ` Alexander Graf
2020-09-02 12:59 ` [PATCH v6 6/7] KVM: x86: Introduce MSR filtering Alexander Graf
2020-09-02 12:59 ` [PATCH v6 7/7] KVM: selftests: Add test for user space MSR handling Alexander Graf
2020-09-03 19:31 ` Aaron Lewis
-- strict thread matches above, loose matches on Subject: below --
2020-09-01 20:15 [PATCH v6 0/7] Allow user space to restrict and augment MSR emulation Alexander Graf
2020-09-01 20:15 ` [PATCH v6 1/7] KVM: x86: Deflect unknown MSR accesses to user space Alexander Graf
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=20200916170839.GD10227@sjchrist-ice \
--to=sean.j.christopherson@intel.com \
--cc=aaronlewis@google.com \
--cc=corbet@lwn.net \
--cc=dan.carpenter@oracle.com \
--cc=graf@amazon.com \
--cc=jmattson@google.com \
--cc=joro@8bytes.org \
--cc=karahmed@amazon.de \
--cc=kvm@vger.kernel.org \
--cc=linux-doc@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=pbonzini@redhat.com \
--cc=vkuznets@redhat.com \
--cc=wanpengli@tencent.com \
/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).