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| author | Marc Zyngier <marc.zyngier@arm.com> | 2013-06-21 14:08:46 +0200 |
|---|---|---|
| committer | Christoffer Dall <christoffer.dall@linaro.org> | 2013-06-26 19:50:04 +0200 |
| commit | 6a077e4ab9cbfbf279fb955bae05b03781c97013 (patch) | |
| tree | 78f18407f328888685939a1f183beebd349e6cc3 /arch/arm/kvm/coproc.c | |
| parent | ARM: KVM: get rid of S2_PGD_SIZE (diff) | |
| download | linux-6a077e4ab9cbfbf279fb955bae05b03781c97013.tar.xz linux-6a077e4ab9cbfbf279fb955bae05b03781c97013.zip | |
ARM: KVM: perform save/restore of PAR
Not saving PAR is an unfortunate oversight. If the guest performs
an AT* operation and gets scheduled out before reading the result
of the translation from PAR, it could become corrupted by another
guest or the host.
Saving this register is made slightly more complicated as KVM also
uses it on the permission fault handling path, leading to an ugly
"stash and restore" sequence. Fortunately, this is already a slow
path so we don't really care. Also, Linux doesn't do any AT*
operation, so Linux guests are not impacted by this bug.
[ Slightly tweaked to use an even register as first operand to ldrd
and strd operations in interrupts_head.S - Christoffer ]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Diffstat (limited to 'arch/arm/kvm/coproc.c')
| -rw-r--r-- | arch/arm/kvm/coproc.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/arm/kvm/coproc.c b/arch/arm/kvm/coproc.c index 8eea97be1ed5..4a5199070430 100644 --- a/arch/arm/kvm/coproc.c +++ b/arch/arm/kvm/coproc.c @@ -180,6 +180,10 @@ static const struct coproc_reg cp15_regs[] = { NULL, reset_unknown, c6_DFAR }, { CRn( 6), CRm( 0), Op1( 0), Op2( 2), is32, NULL, reset_unknown, c6_IFAR }, + + /* PAR swapped by interrupt.S */ + { CRn( 7), Op1( 0), is64, NULL, reset_unknown64, c7_PAR }, + /* * DC{C,I,CI}SW operations: */ |