On Mon, Jun 12, 2023 at 11:07 PM liguang.zhang <18622748...@163.com> wrote: > > From: "liguang.zhang" <liguang.zh...@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.zh...@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 > >