From: Paolo Bonzini <pbonzini@redhat.com>
To: lantianyu1986@gmail.com
Cc: Lan Tianyu <Tianyu.Lan@microsoft.com>,
christoffer.dall@arm.com, marc.zyngier@arm.com,
linux@armlinux.org.uk, catalin.marinas@arm.com,
will.deacon@arm.com, jhogan@kernel.org, ralf@linux-mips.org,
paul.burton@mips.com, paulus@ozlabs.org,
benh@kernel.crashing.org, mpe@ellerman.id.au, rkrcmar@redhat.com,
tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
hpa@zytor.com, x86@kernel.org,
linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org,
linux-mips@vger.kernel.org, kvm-ppc@vger.kernel.org,
linuxppc-dev@lists.ozlabs.org, kvm@vger.kernel.org,
michael.h.kelley@microsoft.com, kys@microsoft.com,
vkuznets@redhat.com
Subject: Re: [PATCH 9/11] KVM/MMU: Flush tlb in the kvm_mmu_write_protect_pt_masked()
Date: Mon, 7 Jan 2019 17:26:35 +0100 [thread overview]
Message-ID: <7eb0cde4-9436-9719-dd13-caf4ab5083a2@redhat.com> (raw)
In-Reply-To: <20190104085405.40356-10-Tianyu.Lan@microsoft.com>
On 04/01/19 09:54, lantianyu1986@gmail.com wrote:
> rmap_head = __gfn_to_rmap(slot->base_gfn + gfn_offset + __ffs(mask),
> PT_PAGE_TABLE_LEVEL, slot);
> - __rmap_write_protect(kvm, rmap_head, false);
> + flush |= __rmap_write_protect(kvm, rmap_head, false);
>
> /* clear the first set bit */
> mask &= mask - 1;
> }
> +
> + if (flush && kvm_available_flush_tlb_with_range()) {
> + kvm_flush_remote_tlbs_with_address(kvm,
> + slot->base_gfn + gfn_offset,
> + hweight_long(mask));
Mask is zero here, so this probably won't work.
In addition, I suspect calling the hypercall once for every 64 pages is
not very efficient. Passing a flush list into
kvm_mmu_write_protect_pt_masked, and flushing in
kvm_arch_mmu_enable_log_dirty_pt_masked, isn't efficient either because
kvm_arch_mmu_enable_log_dirty_pt_masked is also called once per word.
I don't have any good ideas, except for moving the whole
kvm_clear_dirty_log_protect loop into architecture-specific code (which
is not the direction we want---architectures should share more code, not
less).
Paolo
> + flush = false;
> + }
> +
next prev parent reply other threads:[~2019-01-07 16:26 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-04 8:53 [PATCH 00/11] X86/KVM/Hyper-V: Add HV ept tlb range list flush support in KVM lantianyu1986
2019-01-04 8:53 ` [PATCH 1/11] X86/Hyper-V: Add parameter offset for hyperv_fill_flush_guest_mapping_list() lantianyu1986
2019-01-04 8:53 ` [PATCH 2/11] KVM/VMX: Fill range list in kvm_fill_hv_flush_list_func() lantianyu1986
2019-01-04 8:53 ` [PATCH 3/11] KVM: Add spte's point in the struct kvm_mmu_page lantianyu1986
2019-01-07 16:34 ` Paolo Bonzini
2019-01-04 8:53 ` [PATCH 4/11] KVM/MMU: Introduce tlb flush with range list lantianyu1986
2019-01-07 16:39 ` Paolo Bonzini
2019-01-04 8:53 ` [PATCH 5/11] KVM/MMU: Flush tlb directly in the kvm_mmu_slot_gfn_write_protect() lantianyu1986
2019-01-04 8:54 ` [PATCH 6/11] KVM/MMU: Flush tlb with range list in sync_page() lantianyu1986
[not found] ` <20190104163035.GC11288@linux.intel.com>
2019-01-07 5:13 ` Tianyu Lan
2019-01-07 16:07 ` Paolo Bonzini
2019-01-04 8:54 ` [PATCH 7/11] KVM: Remove redundant check in the kvm_get_dirty_log_protect() lantianyu1986
[not found] ` <20190104155036.GA11288@linux.intel.com>
2019-01-04 21:27 ` Sean Christopherson
2019-01-07 16:20 ` Paolo Bonzini
2019-01-04 8:54 ` [PATCH 8/11] KVM: Make kvm_arch_mmu_enable_log_dirty_pt_masked() return value lantianyu1986
2019-01-04 8:54 ` [PATCH 9/11] KVM/MMU: Flush tlb in the kvm_mmu_write_protect_pt_masked() lantianyu1986
2019-01-07 16:26 ` Paolo Bonzini [this message]
2019-01-10 9:06 ` Tianyu Lan
2019-01-04 8:54 ` [PATCH 10/11] KVM: Add flush parameter for kvm_age_hva() lantianyu1986
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=7eb0cde4-9436-9719-dd13-caf4ab5083a2@redhat.com \
--to=pbonzini@redhat.com \
--cc=Tianyu.Lan@microsoft.com \
--cc=benh@kernel.crashing.org \
--cc=bp@alien8.de \
--cc=catalin.marinas@arm.com \
--cc=christoffer.dall@arm.com \
--cc=hpa@zytor.com \
--cc=jhogan@kernel.org \
--cc=kvm-ppc@vger.kernel.org \
--cc=kvm@vger.kernel.org \
--cc=kvmarm@lists.cs.columbia.edu \
--cc=kys@microsoft.com \
--cc=lantianyu1986@gmail.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mips@vger.kernel.org \
--cc=linux@armlinux.org.uk \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=marc.zyngier@arm.com \
--cc=michael.h.kelley@microsoft.com \
--cc=mingo@redhat.com \
--cc=mpe@ellerman.id.au \
--cc=paul.burton@mips.com \
--cc=paulus@ozlabs.org \
--cc=ralf@linux-mips.org \
--cc=rkrcmar@redhat.com \
--cc=tglx@linutronix.de \
--cc=vkuznets@redhat.com \
--cc=will.deacon@arm.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).