[PATCH 02/15] arm/kvm: add accessors for storing host features into idregs

[Cornelia Huck <cohuck@redhat.com>]

Signed-off-by: Cornelia Huck <cohuck@redhat.com>
---
 target/arm/cpu-sysregs.h |  3 +++
 target/arm/cpu64.c       | 25 +++++++++++++++++++++++++
 target/arm/kvm.c         | 30 ++++++++++++++++++++++++++++++
 3 files changed, 58 insertions(+)

diff --git a/target/arm/cpu-sysregs.h b/target/arm/cpu-sysregs.h
index de09ebae91a5..54a4fadbf0c1 100644
--- a/target/arm/cpu-sysregs.h
+++ b/target/arm/cpu-sysregs.h
@@ -128,4 +128,7 @@ static const uint32_t id_register_sysreg[NUM_ID_IDX] = {
     [CTR_EL0_IDX] = SYS_CTR_EL0,
 };
 
+int get_sysreg_idx(ARMSysRegs sysreg);
+uint64_t idregs_sysreg_to_kvm_reg(ARMSysRegs sysreg);
+
 #endif /* ARM_CPU_SYSREGS_H */
diff --git a/target/arm/cpu64.c b/target/arm/cpu64.c
index 8188ede5cc8a..9ae78253cb34 100644
--- a/target/arm/cpu64.c
+++ b/target/arm/cpu64.c
@@ -736,6 +736,31 @@ static void aarch64_a53_initfn(Object *obj)
     define_cortex_a72_a57_a53_cp_reginfo(cpu);
 }
 
+#ifdef CONFIG_KVM
+
+int get_sysreg_idx(ARMSysRegs sysreg)
+{
+    int i;
+
+    for (i = 0; i < NUM_ID_IDX; i++) {
+        if (id_register_sysreg[i] == sysreg) {
+            return i;
+        }
+    }
+    return -1;
+}
+
+uint64_t idregs_sysreg_to_kvm_reg(ARMSysRegs sysreg)
+{
+    return ARM64_SYS_REG((sysreg & CP_REG_ARM64_SYSREG_OP0_MASK) >> CP_REG_ARM64_SYSREG_OP0_SHIFT,
+                         (sysreg & CP_REG_ARM64_SYSREG_OP1_MASK) >> CP_REG_ARM64_SYSREG_OP1_SHIFT,
+                         (sysreg & CP_REG_ARM64_SYSREG_CRN_MASK) >> CP_REG_ARM64_SYSREG_CRN_SHIFT,
+                         (sysreg & CP_REG_ARM64_SYSREG_CRM_MASK) >> CP_REG_ARM64_SYSREG_CRM_SHIFT,
+                         (sysreg & CP_REG_ARM64_SYSREG_OP2_MASK) >> CP_REG_ARM64_SYSREG_OP2_SHIFT);
+}
+
+#endif
+
 static void aarch64_host_initfn(Object *obj)
 {
 #if defined(CONFIG_KVM)
diff --git a/target/arm/kvm.c b/target/arm/kvm.c
index da30bdbb2349..3b8bb5661f2b 100644
--- a/target/arm/kvm.c
+++ b/target/arm/kvm.c
@@ -246,6 +246,36 @@ static bool kvm_arm_pauth_supported(void)
             kvm_check_extension(kvm_state, KVM_CAP_ARM_PTRAUTH_GENERIC));
 }
 
+/* read a 32b sysreg value and store it in the idregs */
+static int get_host_cpu_reg32(int fd, ARMHostCPUFeatures *ahcf, ARMSysRegs sysreg)
+{
+    int index = get_sysreg_idx(sysreg);
+    uint64_t *reg;
+    int ret;
+
+    if (index < 0) {
+        return -ERANGE;
+    }
+    reg = &ahcf->isar.idregs[index];
+    ret = read_sys_reg32(fd, (uint32_t *)reg, idregs_sysreg_to_kvm_reg(sysreg));
+    return ret;
+}
+
+/* read a 64b sysreg value and store it in the idregs */
+static int get_host_cpu_reg64(int fd, ARMHostCPUFeatures *ahcf, ARMSysRegs sysreg)
+{
+    int index = get_sysreg_idx(sysreg);
+    uint64_t *reg;
+    int ret;
+
+    if (index < 0) {
+        return -ERANGE;
+    }
+    reg = &ahcf->isar.idregs[index];
+    ret = read_sys_reg64(fd, reg, idregs_sysreg_to_kvm_reg(sysreg));
+    return ret;
+}
+
 static bool kvm_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf)
 {
     /* Identify the feature bits corresponding to the host CPU, and
-- 
2.48.1