path: root/arch/arm64
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authorMarc Zyngier <marc.zyngier@arm.com>2014-08-01 12:00:36 +0100
committerChristoffer Dall <christoffer.dall@linaro.org>2014-10-02 22:21:49 +0200
commit85a26a96940f616aa6d35d2a2c988dbfef31bf79 (patch)
treed3d267b152f00a487d92eabb73557e45c6ee41a5 /arch/arm64
parent5ed30eec2507d903c66f51d519cc1bca043042a3 (diff)
arm64: KVM: fix 64bit CP15 VM access for 32bit guests
Commit f0a3eaff71b8 (ARM64: KVM: fix big endian issue in access_vm_reg for 32bit guest) changed the way we handle CP15 VM accesses, so that all 64bit accesses are done via vcpu_sys_reg. This looks like a good idea as it solves indianness issues in an elegant way, except for one small detail: the register index is doesn't refer to the same array! We end up corrupting some random data structure instead. Fix this by reverting to the original code, except for the introduction of a vcpu_cp15_64_high macro that deals with the endianness thing. Tested on Juno with 32bit SMP guests. Cc: Victor Kamensky <victor.kamensky@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> (cherry picked from commit dedf97e8ff2c7513b1370e36b56e08b6bd0f0290) Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Diffstat (limited to 'arch/arm64')
2 files changed, 9 insertions, 4 deletions
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 79812be4f25f..e10c45a578e3 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -149,9 +149,11 @@ struct kvm_vcpu_arch {
#define vcpu_cp15(v,r) ((v)->arch.ctxt.copro[(r)])
-#define vcpu_cp15_64_low(v,r) ((v)->arch.ctxt.copro[((r) + 1)])
+#define vcpu_cp15_64_high(v,r) vcpu_cp15((v),(r))
+#define vcpu_cp15_64_low(v,r) vcpu_cp15((v),(r) + 1)
-#define vcpu_cp15_64_low(v,r) ((v)->arch.ctxt.copro[((r) + 0)])
+#define vcpu_cp15_64_high(v,r) vcpu_cp15((v),(r) + 1)
+#define vcpu_cp15_64_low(v,r) vcpu_cp15((v),(r))
struct kvm_vm_stat {
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index a4fd5267c65b..5805e7c4a4dd 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -135,10 +135,13 @@ static bool access_vm_reg(struct kvm_vcpu *vcpu,
val = *vcpu_reg(vcpu, p->Rt);
- if (!p->is_aarch32 || !p->is_32bit)
+ if (!p->is_aarch32) {
vcpu_sys_reg(vcpu, r->reg) = val;
- else
+ } else {
+ if (!p->is_32bit)
+ vcpu_cp15_64_high(vcpu, r->reg) = val >> 32;
vcpu_cp15_64_low(vcpu, r->reg) = val & 0xffffffffUL;
+ }
return true;