From 8b69a1b340da95cacdff252927ca8aef9d43c33a Mon Sep 17 00:00:00 2001
From: Song Gao <gaosong@loongson.cn>
Date: Wed, 24 Apr 2024 16:06:33 +0800
Subject: [PATCH] target/loongarch/kvm: Add pv steal time support

Signed-off-by: Song Gao <gaosong@loongson.cn>
---
 linux-headers/asm-loongarch/kvm.h    |  2 ++
 target/loongarch/cpu.h               |  3 ++
 target/loongarch/kvm/kvm.c           | 50 ++++++++++++++++++++++++++++
 target/loongarch/kvm/kvm_loongarch.h |  2 ++
 target/loongarch/machine.c           | 25 ++++++++++++++
 5 files changed, 82 insertions(+)

diff --git a/linux-headers/asm-loongarch/kvm.h b/linux-headers/asm-loongarch/kvm.h
index 4cec8c1601..81fec85f0a 100644
--- a/linux-headers/asm-loongarch/kvm.h
+++ b/linux-headers/asm-loongarch/kvm.h
@@ -84,6 +84,8 @@ struct kvm_fpu {
 #define KVM_IOC_CSRID(REG)		LOONGARCH_REG_64(KVM_REG_LOONGARCH_CSR, REG)
 #define KVM_IOC_CPUCFG(REG)		LOONGARCH_REG_64(KVM_REG_LOONGARCH_CPUCFG, REG)
 #define KVM_LOONGARCH_VCPU_CPUCFG	0
+#define KVM_LOONGARCH_VCPU_PVTIME_CTRL	1
+#define KVM_LOONGARCH_VCPU_PVTIME_GPA	0
 
 struct kvm_debug_exit_arch {
 };
diff --git a/target/loongarch/cpu.h b/target/loongarch/cpu.h
index 80cad24fa1..0ed24051af 100644
--- a/target/loongarch/cpu.h
+++ b/target/loongarch/cpu.h
@@ -365,6 +365,9 @@ typedef struct CPUArchState {
     /* Store ipistate to access from this struct */
     DeviceState *ipistate;
 #endif
+    struct {
+        uint64_t guest_addr;
+    } st;
 } CPULoongArchState;
 
 /**
diff --git a/target/loongarch/kvm/kvm.c b/target/loongarch/kvm/kvm.c
index 5dda631b2b..e1d521a1de 100644
--- a/target/loongarch/kvm/kvm.c
+++ b/target/loongarch/kvm/kvm.c
@@ -649,6 +649,56 @@ static int kvm_loongarch_put_cpucfg(CPUState *cs)
     return ret;
 }
 
+int kvm_loongarch_put_pvtime(LoongArchCPU *cpu)
+{
+    CPULoongArchState *env = &cpu->env;
+    int err;
+    struct kvm_device_attr attr = {
+        .group = KVM_LOONGARCH_VCPU_PVTIME_CTRL,
+        .attr = KVM_LOONGARCH_VCPU_PVTIME_GPA,
+        .addr = (uint64_t)&env->st.guest_addr,
+    };
+
+    err = kvm_vcpu_ioctl(CPU(cpu), KVM_HAS_DEVICE_ATTR, attr);
+    if (err != 0) {
+        /* It's ok even though kvm has not such attr */
+        return 0;
+    }
+
+    err = kvm_vcpu_ioctl(CPU(cpu), KVM_SET_DEVICE_ATTR, attr);
+    if (err != 0) {
+        error_report("PVTIME IPA: KVM_SET_DEVICE_ATTR: %s", strerror(-err));
+        return err;
+    }
+
+    return 0;
+}
+
+int kvm_loongarch_get_pvtime(LoongArchCPU *cpu)
+{
+    CPULoongArchState *env = &cpu->env;
+    int err;
+    struct kvm_device_attr attr = {
+        .group = KVM_LOONGARCH_VCPU_PVTIME_CTRL,
+        .attr = KVM_LOONGARCH_VCPU_PVTIME_GPA,
+        .addr = (uint64_t)&env->st.guest_addr,
+    };
+
+    err = kvm_vcpu_ioctl(CPU(cpu), KVM_HAS_DEVICE_ATTR, attr);
+    if (err != 0) {
+        /* It's ok even though kvm has not such attr */
+        return 0;
+    }
+
+    err = kvm_vcpu_ioctl(CPU(cpu), KVM_GET_DEVICE_ATTR, attr);
+    if (err != 0) {
+        error_report("PVTIME IPA: KVM_GET_DEVICE_ATTR: %s", strerror(-err));
+        return err;
+    }
+
+    return 0;
+}
+
 int kvm_arch_get_registers(CPUState *cs)
 {
     int ret;
diff --git a/target/loongarch/kvm/kvm_loongarch.h b/target/loongarch/kvm/kvm_loongarch.h
index d945b6bb82..551878a725 100644
--- a/target/loongarch/kvm/kvm_loongarch.h
+++ b/target/loongarch/kvm/kvm_loongarch.h
@@ -12,5 +12,7 @@
 
 int  kvm_loongarch_set_interrupt(LoongArchCPU *cpu, int irq, int level);
 void kvm_arch_reset_vcpu(CPULoongArchState *env);
+int kvm_loongarch_put_pvtime(LoongArchCPU *cpu);
+int kvm_loongarch_get_pvtime(LoongArchCPU *cpu);
 
 #endif
diff --git a/target/loongarch/machine.c b/target/loongarch/machine.c
index 4443caed2d..ec5abe56db 100644
--- a/target/loongarch/machine.c
+++ b/target/loongarch/machine.c
@@ -9,6 +9,8 @@
 #include "cpu.h"
 #include "migration/cpu.h"
 #include "vec.h"
+#include "kvm/kvm_loongarch.h"
+#include "sysemu/kvm.h"
 
 static const VMStateDescription vmstate_fpu_reg = {
     .name = "fpu_reg",
@@ -122,15 +124,38 @@ const VMStateDescription vmstate_tlb = {
     }
 };
 
+static int cpu_post_load(void *opaque, int version_id)
+{
+#ifdef CONFIG_KVM
+    LoongArchCPU *cpu = opaque;
+    kvm_loongarch_put_pvtime(cpu);
+#endif
+    return 0;
+}
+
+static int cpu_pre_save(void *opaque)
+{
+#ifdef CONFIG_KVM
+    LoongArchCPU *cpu = opaque;
+    kvm_loongarch_get_pvtime(cpu);
+#endif
+    return 0;
+}
+
 /* LoongArch CPU state */
 const VMStateDescription vmstate_loongarch_cpu = {
     .name = "cpu",
     .version_id = 1,
     .minimum_version_id = 1,
+    .post_load = cpu_post_load,
+    .pre_save = cpu_pre_save,
     .fields = (VMStateField[]) {
         VMSTATE_UINTTL_ARRAY(env.gpr, LoongArchCPU, 32),
         VMSTATE_UINTTL(env.pc, LoongArchCPU),
 
+        /* PV time */
+        VMSTATE_UINT64(env.st.guest_addr, LoongArchCPU),
+
         /* Remaining CSRs */
         VMSTATE_UINT64(env.CSR_CRMD, LoongArchCPU),
         VMSTATE_UINT64(env.CSR_PRMD, LoongArchCPU),
-- 
2.33.0