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authorMarc Zyngier <marc.zyngier@arm.com>2018-02-06 17:56:07 +0000
committerAlex Shi <alex.shi@linaro.org>2018-03-07 13:15:35 +0800
commit533e045776426b37f8ebdc31422a3db9a97979cf (patch)
tree298e4280b714705ddcb7edb958c72457a6869f65
parent505e7e88ce3570e2d385ce810f8b8047a2f7d186 (diff)
arm64: KVM: Increment PC after handling an SMC trap
commit f5115e8869e1 upstream. When handling an SMC trap, the "preferred return address" is set to that of the SMC, and not the next PC (which is a departure from the behaviour of an SMC that isn't trapped). Increment PC in the handler, as the guest is otherwise forever stuck... Cc: stable@vger.kernel.org Fixes: acfb3b883f6d ("arm64: KVM: Fix SMCCC handling of unimplemented SMC/HVC calls") Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Alex Shi <alex.shi@linaro.org>
-rw-r--r--arch/arm64/kvm/handle_exit.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c
index 2e6e9e99977b..5b56b09d317b 100644
--- a/arch/arm64/kvm/handle_exit.c
+++ b/arch/arm64/kvm/handle_exit.c
@@ -53,7 +53,16 @@ static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run)
static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
+ /*
+ * "If an SMC instruction executed at Non-secure EL1 is
+ * trapped to EL2 because HCR_EL2.TSC is 1, the exception is a
+ * Trap exception, not a Secure Monitor Call exception [...]"
+ *
+ * We need to advance the PC after the trap, as it would
+ * otherwise return to the same address...
+ */
vcpu_set_reg(vcpu, 0, ~0UL);
+ kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
return 1;
}