[3.13.y-ckt stable] Patch "KVM: use slowpath for cross page cached accesses" has been added to staging queue
Kamal Mostafa
kamal at canonical.com
Wed May 27 18:54:28 UTC 2015
This is a note to let you know that I have just added a patch titled
KVM: use slowpath for cross page cached accesses
to the linux-3.13.y-queue branch of the 3.13.y-ckt extended stable tree
which can be found at:
http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.13.y-queue
This patch is scheduled to be released in version 3.13.11-ckt21.
If you, or anyone else, feels it should not be added to this tree, please
reply to this email.
For more information about the 3.13.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable
Thanks.
-Kamal
------
>From 264567623bda81033db563b7ea751a4c60b3dd1f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= <rkrcmar at redhat.com>
Date: Wed, 8 Apr 2015 14:16:48 +0200
Subject: KVM: use slowpath for cross page cached accesses
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
commit ca3f0874723fad81d0c701b63ae3a17a408d5f25 upstream.
kvm_write_guest_cached() does not mark all written pages as dirty and
code comments in kvm_gfn_to_hva_cache_init() talk about NULL memslot
with cross page accesses. Fix all the easy way.
The check is '<= 1' to have the same result for 'len = 0' cache anywhere
in the page. (nr_pages_needed is 0 on page boundary.)
Fixes: 8f964525a121 ("KVM: Allow cross page reads and writes from cached translations.")
Signed-off-by: Radim Krčmář <rkrcmar at redhat.com>
Message-Id: <20150408121648.GA3519 at potion.brq.redhat.com>
Reviewed-by: Wanpeng Li <wanpeng.li at linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini at redhat.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
virt/kvm/kvm_main.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 8d2a98a..db50f4c 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1559,8 +1559,8 @@ int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
ghc->generation = slots->generation;
ghc->len = len;
ghc->memslot = gfn_to_memslot(kvm, start_gfn);
- ghc->hva = gfn_to_hva_many(ghc->memslot, start_gfn, &nr_pages_avail);
- if (!kvm_is_error_hva(ghc->hva) && nr_pages_avail >= nr_pages_needed) {
+ ghc->hva = gfn_to_hva_many(ghc->memslot, start_gfn, NULL);
+ if (!kvm_is_error_hva(ghc->hva) && nr_pages_needed <= 1) {
ghc->hva += offset;
} else {
/*
--
1.9.1
More information about the kernel-team
mailing list