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.
Signed-off-by: Marc Zyngier <marc.zyng...@arm.com>
---
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(-)
diff --git a/arch/arm/kvm/handle_exit.c b/arch/arm/kvm/handle_exit.c
index 230ae4079108..910bd8dabb3c 100644
--- 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 *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;
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;
diff --git a/include/kvm/arm_psci.h b/include/kvm/arm_psci.h
index 4ee098c39e01..7b2e12697d4f 100644
--- a/include/kvm/arm_psci.h
+++ b/include/kvm/arm_psci.h
@@ -27,7 +27,7 @@
#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);
struct kvm_one_reg;
diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h
index 4c5bca38c653..dc68aa5a7261 100644
--- 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>
diff --git a/virt/kvm/arm/psci.c b/virt/kvm/arm/psci.c
index 5c8366b71639..53272e8e0d37 100644
--- 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/uaccess.h>
@@ -351,6 +352,7 @@ static int kvm_psci_1_0_call(struct kvm_vcpu *vcpu)
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:
@@ -405,7 +407,7 @@ static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu)
* 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:
@@ -419,6 +421,26 @@ int kvm_psci_call(struct kvm_vcpu *vcpu)
};
}
+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;
+}
+
int kvm_arm_get_fw_num_regs(struct kvm_vcpu *vcpu)
{
return 1; /* PSCI version */
--
2.14.2
