From: Avi Kivity <avi@redhat.com>
To: Xin Tong <xerox.time.tech@gmail.com>
Cc: qemu-devel <qemu-devel@nongnu.org>, KVM list <kvm@vger.kernel.org>
Subject: Re: INVLPG and IPI emulation in KVM
Date: Sun, 13 Nov 2011 14:44:41 +0200 [thread overview]
Message-ID: <4EBFBBB9.60106@redhat.com> (raw)
In-Reply-To: <CALKntY3qmMQcMhFy9pSqQrRgYyzRo0A1_bkQ+=z4Mx-QQsECew@mail.gmail.com>
On 11/13/2011 02:27 PM, Xin Tong wrote:
> I am investigating how INVLPG is emulated in kvm.
You're on the wrong list.
> It turns out that it calls
>
> kvm_mmu_invlpg
> kvm_mmu_flush_tlb
> kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
>
> and the kvm_make_request set the vcpu->requests bit to high, when the
> guest os resumes, it handles the bit. I have 2 questions
>
>
> 1. How does the make_request mechanism work ?
See vcpu_enter_guest().
> how does the guest
> handle the requests ?
The guest never sees them, this is all internal to kvm.
> 2. INVLPG invalidates a tlb entry, it is typically used when the page
> table changes. However, an ipi is typically used to invalidate the tlb
> entries in other processor cores, However, i can not find the
> emulation code for IPI instruction.
There is no IPI instruction, see lapic.c:apic_send_ipi().
--
error compiling committee.c: too many arguments to function
WARNING: multiple messages have this Message-ID (diff)
From: Avi Kivity <avi@redhat.com>
To: Xin Tong <xerox.time.tech@gmail.com>
Cc: qemu-devel <qemu-devel@nongnu.org>, KVM list <kvm@vger.kernel.org>
Subject: Re: [Qemu-devel] INVLPG and IPI emulation in KVM
Date: Sun, 13 Nov 2011 14:44:41 +0200 [thread overview]
Message-ID: <4EBFBBB9.60106@redhat.com> (raw)
In-Reply-To: <CALKntY3qmMQcMhFy9pSqQrRgYyzRo0A1_bkQ+=z4Mx-QQsECew@mail.gmail.com>
On 11/13/2011 02:27 PM, Xin Tong wrote:
> I am investigating how INVLPG is emulated in kvm.
You're on the wrong list.
> It turns out that it calls
>
> kvm_mmu_invlpg
> kvm_mmu_flush_tlb
> kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
>
> and the kvm_make_request set the vcpu->requests bit to high, when the
> guest os resumes, it handles the bit. I have 2 questions
>
>
> 1. How does the make_request mechanism work ?
See vcpu_enter_guest().
> how does the guest
> handle the requests ?
The guest never sees them, this is all internal to kvm.
> 2. INVLPG invalidates a tlb entry, it is typically used when the page
> table changes. However, an ipi is typically used to invalidate the tlb
> entries in other processor cores, However, i can not find the
> emulation code for IPI instruction.
There is no IPI instruction, see lapic.c:apic_send_ipi().
--
error compiling committee.c: too many arguments to function
next prev parent reply other threads:[~2011-11-13 12:44 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-13 12:27 [Qemu-devel] INVLPG and IPI emulation in KVM Xin Tong
2011-11-13 12:44 ` Avi Kivity [this message]
2011-11-13 12:44 ` Avi Kivity
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=4EBFBBB9.60106@redhat.com \
--to=avi@redhat.com \
--cc=kvm@vger.kernel.org \
--cc=qemu-devel@nongnu.org \
--cc=xerox.time.tech@gmail.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.