On 11/26/24 5:56 AM, Jean-Philippe Brucker wrote:
The target code calls kvm_arm_vcpu_init() to mark the vCPU as part of a
Realm. For a Realm vCPU, only x0-x7 can be set at runtime. Before boot,
the PC can also be set, and is ignored at runtime. KVM also accepts a
few system register changes during initial configuration, as returned by
KVM_GET_REG_LIST.
Signed-off-by: Jean-Philippe Brucker <jean-phili...@linaro.org>
---
target/arm/cpu.h | 3 +++
target/arm/kvm_arm.h | 15 +++++++++++
target/arm/kvm-rme.c | 10 ++++++++
target/arm/kvm.c | 61 ++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 89 insertions(+)
diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index d86e641280..f617591921 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -961,6 +961,9 @@ struct ArchCPU {
OnOffAuto kvm_steal_time;
#endif /* CONFIG_KVM */
+ /* Realm Management Extension */
+ bool kvm_rme;
+
/* Uniprocessor system with MP extensions */
bool mp_is_up;
diff --git a/target/arm/kvm_arm.h b/target/arm/kvm_arm.h
index 9d6a89f9b1..8b52a881b0 100644
--- a/target/arm/kvm_arm.h
+++ b/target/arm/kvm_arm.h
@@ -245,6 +245,16 @@ int kvm_arm_rme_init(MachineState *ms);
*/
int kvm_arm_rme_vm_type(MachineState *ms);
+/**
+ * kvm_arm_rme_vcpu_init
+ * @cs: the CPU
+ *
+ * If the user requested a Realm, setup the given vCPU accordingly. Realm vCPUs
+ * behave a little differently, for example most of their register state is
+ * hidden from the host.
+ */
+int kvm_arm_rme_vcpu_init(CPUState *cs);
+
#else
/*
@@ -339,6 +349,11 @@ static inline int kvm_arm_rme_vm_type(MachineState *ms)
g_assert_not_reached();
}
+static inline int kvm_arm_rme_vcpu_init(CPUState *cs)
+{
+ g_assert_not_reached();
+}
+
#endif
#endif
diff --git a/target/arm/kvm-rme.c b/target/arm/kvm-rme.c
index 60d967a842..e3cc37538a 100644
--- a/target/arm/kvm-rme.c
+++ b/target/arm/kvm-rme.c
@@ -137,6 +137,16 @@ int kvm_arm_rme_init(MachineState *ms)
return 0;
}
+int kvm_arm_rme_vcpu_init(CPUState *cs)
+{
+ ARMCPU *cpu = ARM_CPU(cs);
+
+ if (rme_guest) {
+ cpu->kvm_rme = true;
+ }
+ return 0;
+}
+
int kvm_arm_rme_vm_type(MachineState *ms)
{
if (rme_guest) {
diff --git a/target/arm/kvm.c b/target/arm/kvm.c
index 0c80992f7c..a0de2efc41 100644
--- a/target/arm/kvm.c
+++ b/target/arm/kvm.c
@@ -1926,6 +1926,11 @@ int kvm_arch_init_vcpu(CPUState *cs)
return ret;
}
+ ret = kvm_arm_rme_vcpu_init(cs);
+ if (ret) {
+ return ret;
+ }
+
if (cpu_isar_feature(aa64_sve, cpu)) {
ret = kvm_arm_sve_set_vls(cpu);
if (ret) {
@@ -2062,6 +2067,35 @@ static int kvm_arch_put_sve(CPUState *cs)
return 0;
}
+static int kvm_arm_rme_put_core_regs(CPUState *cs, Error **errp)
+{
+ int i, ret;
+ struct kvm_one_reg reg;
+ ARMCPU *cpu = ARM_CPU(cs);
+ CPUARMState *env = &cpu->env;
+
+ /*
+ * The RME ABI only allows us to set 8 GPRs and the PC
+ */
Needn't to span for multiple lines.
+ for (i = 0; i < 8; i++) {
+ reg.id = AARCH64_CORE_REG(regs.regs[i]);
+ reg.addr = (uintptr_t) &env->xregs[i];
+ ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, ®);
+ if (ret) {
+ return ret;
+ }
+ }
+
+ reg.id = AARCH64_CORE_REG(regs.pc);
+ reg.addr = (uintptr_t) &env->pc;
+ ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, ®);
+ if (ret) {
+ return ret;
+ }
+
+ return 0;
+}
+
Nice place to use kvm_set_one_reg(). With it, @reg can be dropped.
static int kvm_arm_put_core_regs(CPUState *cs, int level, Error **errp)
{
uint64_t val;
@@ -2072,6 +2106,10 @@ static int kvm_arm_put_core_regs(CPUState *cs, int
level, Error **errp)
ARMCPU *cpu = ARM_CPU(cs);
CPUARMState *env = &cpu->env;
+ if (cpu->kvm_rme) {
+ return kvm_arm_rme_put_core_regs(cs, errp);
+ }
+
/* If we are in AArch32 mode then we need to copy the AArch32 regs to the
* AArch64 registers before pushing them out to 64-bit KVM.
*/
@@ -2259,6 +2297,25 @@ static int kvm_arch_get_sve(CPUState *cs)
return 0;
}
+static int kvm_arm_rme_get_core_regs(CPUState *cs, Error **errp)
+{
+ int i, ret;
+ struct kvm_one_reg reg;
+ ARMCPU *cpu = ARM_CPU(cs);
+ CPUARMState *env = &cpu->env;
+
+ for (i = 0; i < 8; i++) {
+ reg.id = AARCH64_CORE_REG(regs.regs[i]);
+ reg.addr = (uintptr_t) &env->xregs[i];
+ ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, ®);
+ if (ret) {
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
Similiarly, kvm_get_one_reg() can be used.
static int kvm_arm_get_core_regs(CPUState *cs, Error **errp)
{
uint64_t val;
@@ -2269,6 +2326,10 @@ static int kvm_arm_get_core_regs(CPUState *cs, Error
**errp)
ARMCPU *cpu = ARM_CPU(cs);
CPUARMState *env = &cpu->env;
+ if (cpu->kvm_rme) {
+ return kvm_arm_rme_get_core_regs(cs, errp);
+ }
+
for (i = 0; i < 31; i++) {
ret = kvm_get_one_reg(cs, AARCH64_CORE_REG(regs.regs[i]),
&env->xregs[i]);
Thanks,
Gavin
