From c0938c72f8070aabb766b06edba85941ea7911da Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 6 Feb 2018 17:56:05 +0000 Subject: arm64: KVM: Fix SMCCC handling of unimplemented SMC/HVC calls KVM doesn't follow the SMCCC when it comes to unimplemented calls, and inject an UNDEF instead of returning an error. Since firmware calls are now used for security mitigation, they are becoming more common, and the undef is counter productive. Instead, let's follow the SMCCC which states that -1 must be returned to the caller when getting an unknown function number. Signed-off-by: Marc Zyngier Signed-off-by: Christoffer Dall Signed-off-by: Catalin Marinas --- arch/arm64/kvm/handle_exit.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/arm64/kvm/handle_exit.c') diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c index c09fc5a576c7..520b0dad3c62 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -53,7 +53,7 @@ static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run) ret = kvm_psci_call(vcpu); if (ret < 0) { - kvm_inject_undefined(vcpu); + vcpu_set_reg(vcpu, 0, ~0UL); return 1; } @@ -62,7 +62,7 @@ static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run) static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run) { - kvm_inject_undefined(vcpu); + vcpu_set_reg(vcpu, 0, ~0UL); return 1; } -- cgit v1.2.1 From f5115e8869e1dfafac0e414b4f1664f3a84a4683 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 6 Feb 2018 17:56:07 +0000 Subject: arm64: KVM: Increment PC after handling an SMC trap 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 Tested-by: Ard Biesheuvel Signed-off-by: Marc Zyngier Signed-off-by: Catalin Marinas --- arch/arm64/kvm/handle_exit.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'arch/arm64/kvm/handle_exit.c') diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c index 520b0dad3c62..5493bbefbd0d 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -62,7 +62,16 @@ 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; } -- cgit v1.2.1 From 1a2fb94e6a771ff94f4afa22497a4695187b820c Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 6 Feb 2018 17:56:08 +0000 Subject: arm/arm64: KVM: Consolidate the PSCI include files As we're about to update the PSCI support, and because I'm lazy, let's move the PSCI include file to include/kvm so that both ARM architectures can find it. Acked-by: Christoffer Dall Tested-by: Ard Biesheuvel Signed-off-by: Marc Zyngier Signed-off-by: Catalin Marinas --- arch/arm64/kvm/handle_exit.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'arch/arm64/kvm/handle_exit.c') diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c index 5493bbefbd0d..588f910632a7 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -22,13 +22,14 @@ #include #include +#include + #include #include #include #include #include #include -#include #include #include -- cgit v1.2.1 From 09e6be12effdb33bf7210c8867bbd213b66a499e Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 6 Feb 2018 17:56:12 +0000 Subject: arm/arm64: KVM: Advertise SMCCC v1.1 The new SMC Calling Convention (v1.1) allows for a reduced overhead when calling into the firmware, and provides a new feature discovery mechanism. Make it visible to KVM guests. Tested-by: Ard Biesheuvel Reviewed-by: Christoffer Dall Signed-off-by: Marc Zyngier Signed-off-by: Catalin Marinas --- arch/arm64/kvm/handle_exit.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/arm64/kvm/handle_exit.c') diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c index 588f910632a7..e5e741bfffe1 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -52,7 +52,7 @@ static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run) kvm_vcpu_hvc_get_imm(vcpu)); vcpu->stat.hvc_exit_stat++; - ret = kvm_psci_call(vcpu); + ret = kvm_hvc_call_handler(vcpu); if (ret < 0) { vcpu_set_reg(vcpu, 0, ~0UL); return 1; -- cgit v1.2.1