---- Replied Message ----
On Mon, Jun 12, 2023 at 11:07 PM liguang.zhang <18622748025@163.com> wrote:
From: "liguang.zhang" <liguang.zhang@hexintek.com>
Hello, thanks for the patch
There have a issue of guest reboot bug in kvm-mode:
1. in guest shell just run the reboot, guest can't reboot success, and host kvm stop the vcpu schedual.
2. for smp guest, ctrl+a+c switch to qemu command, use system_reset command to reset the guest, then vcpu crash
There are two issues when rebooting a guest using KVM
1. When the guest initiates a reboot the host is unable to stop the vcpu
2. When running a SMP guest the qemu monitor system_reset causes a vcpu crash
This can be fixed by clearing the CSR values at reset and syncing the
MPSTATE with the host.
kernel log
```shell
$reboot
The system is going down NOW!
Sent SIGTERM to all processes
logout
Sent SIGKILL to all processes
Requesting system reboot
```
then no response
for qemu command:
$system_reset:
kernel log:
```shell
[ 53.739556] kvm [150]: VCPU exit error -95
[ 53.739563] kvm [148]: VCPU exit error -95
[ 53.739557] kvm [149]: VCPU exit error -95
[ 53.740957] kvm [149]: SEPC=0x0 SSTATUS=0x200004120 HSTATUS=0x2002001c0
[ 53.740957] kvm [148]: SEPC=0x0 SSTATUS=0x200004120 HSTATUS=0x2002001c0
[ 53.741054] kvm [148]: SCAUSE=0x14 STVAL=0x0 HTVAL=0x0 HTINST=0x0
[ 53.741058] kvm [149]: SCAUSE=0x14 STVAL=0x0 HTVAL=0x0 HTINST=0x0
[ 53.756187] kvm [150]: SEPC=0x0 SSTATUS=0x200004120 HSTATUS=0x2002001c0
[ 53.757797] kvm [150]: SCAUSE=0x14 STVAL=0x0 HTVAL=0x0 HTINST=0x0
```
solution:
add reset csr and context for riscv vcpu
qemu ioctl reset vcpu->arch.power_off state of kvm
tests:
qemu-system-riscv64 -M virt -bios none -kernel Image \
-smp 4 -enable-kvm \
-append "rootwait root=/dev/vda ro" \
-drive file=rootfs.ext2,format=raw,id=hd0 \
-device virtio-blk-device,drive=hd0
in guest shell:
$reboot
qemu command:
$system_reset
---
v2:
- update submit description
Signed-off-by: liguang.zhang <liguang.zhang@hexintek.com>
---
target/riscv/kvm.c | 43 ++++++++++++++++++++++++++++++++++++++++
target/riscv/kvm_riscv.h | 1 +
2 files changed, 44 insertions(+)
diff --git a/target/riscv/kvm.c b/target/riscv/kvm.c
index 0f932a5b96..c6a7824c9e 100644
--- a/target/riscv/kvm.c
+++ b/target/riscv/kvm.c
@@ -42,6 +42,8 @@
#include "migration/migration.h"
#include "sysemu/runstate.h"
+static bool cap_has_mp_state;
+
static uint64_t kvm_riscv_reg_id(CPURISCVState *env, uint64_t type,
uint64_t idx)
{
@@ -335,6 +337,25 @@ int kvm_arch_get_registers(CPUState *cs)
return ret;
}
+int kvm_riscv_set_mpstate_to_kvm(RISCVCPU *cpu, int state)
This should probably be called:
kvm_riscv_sync_mpstate_to_kvm()
instead
+{
+ if (cap_has_mp_state) {
+
No newline required
Otherwise the patch looks good
Alistair
+ struct kvm_mp_state mp_state = {
+ .mp_state = state
+ };
+
+ int ret = kvm_vcpu_ioctl(CPU(cpu), KVM_SET_MP_STATE, &mp_state);
+ if (ret) {
+ fprintf(stderr, "%s: failed to set MP_STATE %d/%s\n",
+ __func__, ret, strerror(-ret));
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
int kvm_arch_put_registers(CPUState *cs, int level)
{
int ret = 0;
@@ -354,6 +375,18 @@ int kvm_arch_put_registers(CPUState *cs, int level)
return ret;
}
+ if (KVM_PUT_RESET_STATE == level) {
+ RISCVCPU *cpu = RISCV_CPU(cs);
+ if (cs->cpu_index == 0) {
+ ret = kvm_riscv_set_mpstate_to_kvm(cpu, KVM_MP_STATE_RUNNABLE);
+ } else {
+ ret = kvm_riscv_set_mpstate_to_kvm(cpu, KVM_MP_STATE_STOPPED);
+ }
+ if (ret) {
+ return ret;
+ }
+ }
+
return ret;
}
@@ -428,6 +461,7 @@ int kvm_arch_add_msi_route_post(struct kvm_irq_routing_entry *route,
int kvm_arch_init(MachineState *ms, KVMState *s)
{
+ cap_has_mp_state = kvm_check_extension(s, KVM_CAP_MP_STATE);
return 0;
}
@@ -506,10 +540,19 @@ void kvm_riscv_reset_vcpu(RISCVCPU *cpu)
if (!kvm_enabled()) {
return;
}
+ for (int i=0; i<32; i++)
+ env->gpr[i] = 0;
env->pc = cpu->env.kernel_addr;
env->gpr[10] = kvm_arch_vcpu_id(CPU(cpu)); /* a0 */
env->gpr[11] = cpu->env.fdt_addr; /* a1 */
env->satp = 0;
+ env->mie = 0;
+ env->stvec = 0;
+ env->sscratch = 0;
+ env->sepc = 0;
+ env->scause = 0;
+ env->stval = 0;
+ env->mip = 0;
}
void kvm_riscv_set_irq(RISCVCPU *cpu, int irq, int level)
diff --git a/target/riscv/kvm_riscv.h b/target/riscv/kvm_riscv.h
index ed281bdce0..4a4c262820 100644
--- a/target/riscv/kvm_riscv.h
+++ b/target/riscv/kvm_riscv.h
@@ -21,5 +21,6 @@
void kvm_riscv_reset_vcpu(RISCVCPU *cpu);
void kvm_riscv_set_irq(RISCVCPU *cpu, int irq, int level);
+int kvm_riscv_set_mpstate_to_kvm(RISCVCPU *cpu, int state);
#endif
--
2.17.1