Hi,
Not familiar with kvm. And I have a question about this patch. Maybe
backport this patch 3204be4109ad("KVM: arm64: Make vcpu_cp1x() work on
Big Endian hosts") without 52f6c4f02164 ("KVM: arm64: Change 32-bit
handling of VM system registers") seems not right?
Thanks,
Kun.
在 2020/6/16 18:56, gre...@linuxfoundation.org 写道:
This is a note to let you know that I've just added the patch titled
KVM: arm64: Make vcpu_cp1x() work on Big Endian hosts
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
kvm-arm64-make-vcpu_cp1x-work-on-big-endian-hosts.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let know about it.
From 3204be4109ad681523e3461ce64454c79278450a Mon Sep 17 00:00:00 2001
From: Marc Zyngier
Date: Tue, 9 Jun 2020 08:40:35 +0100
Subject: KVM: arm64: Make vcpu_cp1x() work on Big Endian hosts
From: Marc Zyngier
commit 3204be4109ad681523e3461ce64454c79278450a upstream.
AArch32 CP1x registers are overlayed on their AArch64 counterparts
in the vcpu struct. This leads to an interesting problem as they
are stored in their CPU-local format, and thus a CP1x register
doesn't "hit" the lower 32bit portion of the AArch64 register on
a BE host.
To workaround this unfortunate situation, introduce a bias trick
in the vcpu_cp1x() accessors which picks the correct half of the
64bit register.
Cc: sta...@vger.kernel.org
Reported-by: James Morse
Tested-by: James Morse
Acked-by: James Morse
Signed-off-by: Marc Zyngier
Signed-off-by: Greg Kroah-Hartman
---
arch/arm64/include/asm/kvm_host.h |6 --
1 file changed, 4 insertions(+), 2 deletions(-)
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -178,8 +178,10 @@ struct kvm_vcpu_arch {
* CP14 and CP15 live in the same array, as they are backed by the
* same system registers.
*/
-#define vcpu_cp14(v,r) ((v)->arch.ctxt.copro[(r)])
-#define vcpu_cp15(v,r) ((v)->arch.ctxt.copro[(r)])
+#define CPx_BIAS IS_ENABLED(CONFIG_CPU_BIG_ENDIAN)
+
+#define vcpu_cp14(v,r) ((v)->arch.ctxt.copro[(r) ^ CPx_BIAS])
+#define vcpu_cp15(v,r) ((v)->arch.ctxt.copro[(r) ^ CPx_BIAS])
#ifdef CONFIG_CPU_BIG_ENDIAN
#define vcpu_cp15_64_high(v,r)vcpu_cp15((v),(r))
Patches currently in stable-queue which might be from m...@kernel.org are
queue-4.4/kvm-arm64-make-vcpu_cp1x-work-on-big-endian-hosts.patch
.
