4.15-stable review patch. If anyone has any objections, please let me know.
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From: Marc Zyngier marc.zyngier@arm.com
Commit 09e6be12effd upstream.
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 ard.biesheuvel@linaro.org Reviewed-by: Christoffer Dall christoffer.dall@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: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/arm/kvm/handle_exit.c | 2 +- arch/arm64/kvm/handle_exit.c | 2 +- include/kvm/arm_psci.h | 2 +- include/linux/arm-smccc.h | 13 +++++++++++++ virt/kvm/arm/psci.c | 24 +++++++++++++++++++++++- 5 files changed, 39 insertions(+), 4 deletions(-)
--- a/arch/arm/kvm/handle_exit.c +++ b/arch/arm/kvm/handle_exit.c @@ -36,7 +36,7 @@ static int handle_hvc(struct kvm_vcpu *v 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) { kvm_inject_undefined(vcpu); return 1; --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -44,7 +44,7 @@ static int handle_hvc(struct kvm_vcpu *v 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; --- a/include/kvm/arm_psci.h +++ b/include/kvm/arm_psci.h @@ -27,6 +27,6 @@ #define KVM_ARM_PSCI_LATEST KVM_ARM_PSCI_1_0
int kvm_psci_version(struct kvm_vcpu *vcpu); -int kvm_psci_call(struct kvm_vcpu *vcpu); +int kvm_hvc_call_handler(struct kvm_vcpu *vcpu);
#endif /* __KVM_ARM_PSCI_H__ */ --- a/include/linux/arm-smccc.h +++ b/include/linux/arm-smccc.h @@ -60,6 +60,19 @@ #define ARM_SMCCC_QUIRK_NONE 0 #define ARM_SMCCC_QUIRK_QCOM_A6 1 /* Save/restore register a6 */
+#define ARM_SMCCC_VERSION_1_0 0x10000 +#define ARM_SMCCC_VERSION_1_1 0x10001 + +#define ARM_SMCCC_VERSION_FUNC_ID \ + ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \ + ARM_SMCCC_SMC_32, \ + 0, 0) + +#define ARM_SMCCC_ARCH_FEATURES_FUNC_ID \ + ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \ + ARM_SMCCC_SMC_32, \ + 0, 1) + #ifndef __ASSEMBLY__
#include <linux/linkage.h> --- a/virt/kvm/arm/psci.c +++ b/virt/kvm/arm/psci.c @@ -15,6 +15,7 @@ * along with this program. If not, see http://www.gnu.org/licenses/. */
+#include <linux/arm-smccc.h> #include <linux/preempt.h> #include <linux/kvm_host.h> #include <linux/wait.h> @@ -339,6 +340,7 @@ static int kvm_psci_1_0_call(struct kvm_ case PSCI_0_2_FN_SYSTEM_OFF: case PSCI_0_2_FN_SYSTEM_RESET: case PSCI_1_0_FN_PSCI_FEATURES: + case ARM_SMCCC_VERSION_FUNC_ID: val = 0; break; default: @@ -393,7 +395,7 @@ static int kvm_psci_0_1_call(struct kvm_ * Errors: * -EINVAL: Unrecognized PSCI function */ -int kvm_psci_call(struct kvm_vcpu *vcpu) +static int kvm_psci_call(struct kvm_vcpu *vcpu) { switch (kvm_psci_version(vcpu)) { case KVM_ARM_PSCI_1_0: @@ -406,3 +408,23 @@ int kvm_psci_call(struct kvm_vcpu *vcpu) return -EINVAL; }; } + +int kvm_hvc_call_handler(struct kvm_vcpu *vcpu) +{ + u32 func_id = smccc_get_function(vcpu); + u32 val = PSCI_RET_NOT_SUPPORTED; + + switch (func_id) { + case ARM_SMCCC_VERSION_FUNC_ID: + val = ARM_SMCCC_VERSION_1_1; + break; + case ARM_SMCCC_ARCH_FEATURES_FUNC_ID: + /* Nothing supported yet */ + break; + default: + return kvm_psci_call(vcpu); + } + + smccc_set_retval(vcpu, val, 0, 0, 0); + return 1; +}