On Sat, Nov 20, 2021 at 1:17 PM Yifei Jiang <jiangyifei(a)huawei.com> wrote:
Add kvm_riscv_get/put_regs_timer to synchronize virtual time context
from KVM.
To set register of RISCV_TIMER_REG(state) will occur a error from KVM
on kvm_timer_state == 0. It's better to adapt in KVM, but it doesn't matter
that adaping in QEMU.
Signed-off-by: Yifei Jiang <jiangyifei(a)huawei.com>
Signed-off-by: Mingwang Li <limingwang(a)huawei.com>
---
target/riscv/cpu.h | 6 ++++
target/riscv/kvm.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 78 insertions(+)
diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index e7dba35acb..dea49e53f0 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -259,6 +259,12 @@ struct CPURISCVState {
hwaddr kernel_addr;
hwaddr fdt_addr;
+
+ /* kvm timer */
+ bool kvm_timer_dirty;
+ uint64_t kvm_timer_time;
+ uint64_t kvm_timer_compare;
+ uint64_t kvm_timer_state;
We should also include kvm_timer_frequency here.
Currently, it is read-only but in-future KVM RISC-V will allow
setting timer_frequency using SBI para-virt time scaling extension.
Regards,
Anup
};
OBJECT_DECLARE_TYPE(RISCVCPU, RISCVCPUClass,
diff --git a/target/riscv/kvm.c b/target/riscv/kvm.c
index 6d419ba02e..e5725770f2 100644
--- a/target/riscv/kvm.c
+++ b/target/riscv/kvm.c
@@ -64,6 +64,9 @@ static uint64_t kvm_riscv_reg_id(CPURISCVState *env, uint64_t type,
uint64_t idx
#define RISCV_CSR_REG(env, name) kvm_riscv_reg_id(env, KVM_REG_RISCV_CSR, \
KVM_REG_RISCV_CSR_REG(name))
+#define RISCV_TIMER_REG(env, name) kvm_riscv_reg_id(env, KVM_REG_RISCV_TIMER, \
+ KVM_REG_RISCV_TIMER_REG(name))
+
#define RISCV_FP_F_REG(env, idx) kvm_riscv_reg_id(env, KVM_REG_RISCV_FP_F, idx)
#define RISCV_FP_D_REG(env, idx) kvm_riscv_reg_id(env, KVM_REG_RISCV_FP_D, idx)
@@ -310,6 +313,75 @@ static int kvm_riscv_put_regs_fp(CPUState *cs)
return ret;
}
+static void kvm_riscv_get_regs_timer(CPUState *cs)
+{
+ int ret;
+ uint64_t reg;
+ CPURISCVState *env = &RISCV_CPU(cs)->env;
+
+ if (env->kvm_timer_dirty) {
+ return;
+ }
+
+ ret = kvm_get_one_reg(cs, RISCV_TIMER_REG(env, time), ®);
+ if (ret) {
+ abort();
+ }
+ env->kvm_timer_time = reg;
+
+ ret = kvm_get_one_reg(cs, RISCV_TIMER_REG(env, compare), ®);
+ if (ret) {
+ abort();
+ }
+ env->kvm_timer_compare = reg;
+
+ ret = kvm_get_one_reg(cs, RISCV_TIMER_REG(env, state), ®);
+ if (ret) {
+ abort();
+ }
+ env->kvm_timer_state = reg;
+
+ env->kvm_timer_dirty = true;
+}
+
+static void kvm_riscv_put_regs_timer(CPUState *cs)
+{
+ int ret;
+ uint64_t reg;
+ CPURISCVState *env = &RISCV_CPU(cs)->env;
+
+ if (!env->kvm_timer_dirty) {
+ return;
+ }
+
+ reg = env->kvm_timer_time;
+ ret = kvm_set_one_reg(cs, RISCV_TIMER_REG(env, time), ®);
+ if (ret) {
+ abort();
+ }
+
+ reg = env->kvm_timer_compare;
+ ret = kvm_set_one_reg(cs, RISCV_TIMER_REG(env, compare), ®);
+ if (ret) {
+ abort();
+ }
+
+ /*
+ * To set register of RISCV_TIMER_REG(state) will occur a error from KVM
+ * on env->kvm_timer_state == 0, It's better to adapt in KVM, but it
+ * doesn't matter that adaping in QEMU now.
+ * TODO If KVM changes, adapt here.
+ */
+ if (env->kvm_timer_state) {
+ reg = env->kvm_timer_state;
+ ret = kvm_set_one_reg(cs, RISCV_TIMER_REG(env, state), ®);
+ if (ret) {
+ abort();
+ }
+ }
+
+ env->kvm_timer_dirty = false;
+}
const KVMCapabilityInfo kvm_arch_required_capabilities[] = {
KVM_CAP_LAST_INFO
--
2.19.1
--
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