For PAPR guests, KVM tracks the various areas registered with the H_REGISTER_VPA hypercall. For full emulation, of course, these are tracked within qemu. At present these values are not synchronized. This is a problem for reset (qemu's reset of the VPA address is not pushed to KVM) and will also be a problem for savevm / migration.
The kernel now supports accessing the VPA state via the ONE_REG interface, this patch adds code to qemu to use that interface to keep the qemu and KVM ideas of the VPA state synchronized. Signed-off-by: David Gibson <da...@gibson.dropbear.id.au> --- target-ppc/kvm.c | 120 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 120 insertions(+) diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c index 6a676cc..7d06ad9 100644 --- a/target-ppc/kvm.c +++ b/target-ppc/kvm.c @@ -63,6 +63,7 @@ static int cap_ppc_rma; static int cap_spapr_tce; static int cap_hior; static int cap_one_reg; +static int cap_papr; /* XXX We have a race condition where we actually have a level triggered * interrupt, but the infrastructure can't expose that yet, so the guest @@ -95,6 +96,8 @@ int kvm_arch_init(KVMState *s) cap_spapr_tce = kvm_check_extension(s, KVM_CAP_SPAPR_TCE); cap_one_reg = kvm_check_extension(s, KVM_CAP_ONE_REG); cap_hior = kvm_check_extension(s, KVM_CAP_PPC_HIOR); + /* Note: we don't set cap_papr here, because this capability is + * only activated after this by kvmppc_set_papr() */ if (!cap_interrupt_level) { fprintf(stderr, "KVM: Couldn't find level irq capability. Expect the " @@ -652,6 +655,103 @@ static int kvm_get_fp(CPUState *cs) return 0; } +#if defined(TARGET_PPC64) +static int kvm_get_vpa(CPUState *cs) +{ + PowerPCCPU *cpu = POWERPC_CPU(cs); + CPUPPCState *env = &cpu->env; + struct kvm_one_reg reg; + int ret; + + reg.id = KVM_REG_PPC_VPA_ADDR; + reg.addr = (uintptr_t)&env->vpa_addr; + ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, ®); + if (ret < 0) { + dprintf("Unable to get VPA address from KVM: %s\n", strerror(errno)); + return ret; + } + + assert((uintptr_t)&env->slb_shadow_size + == ((uintptr_t)&env->slb_shadow_addr + 8)); + reg.id = KVM_REG_PPC_VPA_SLB; + reg.addr = (uintptr_t)&env->slb_shadow_addr; + ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, ®); + if (ret < 0) { + dprintf("Unable to get SLB shadow state from KVM: %s\n", + strerror(errno)); + return ret; + } + + assert((uintptr_t)&env->dtl_size == ((uintptr_t)&env->dtl_addr + 8)); + reg.id = KVM_REG_PPC_VPA_DTL; + reg.addr = (uintptr_t)&env->dtl_addr; + ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, ®); + if (ret < 0) { + dprintf("Unable to get dispatch trace log state from KVM: %s\n", + strerror(errno)); + return ret; + } + + return 0; +} + +static int kvm_put_vpa(CPUState *cs) +{ + PowerPCCPU *cpu = POWERPC_CPU(cs); + CPUPPCState *env = &cpu->env; + struct kvm_one_reg reg; + int ret; + + /* SLB shadow or DTL can't be registered unless a master VPA is + * registered. That means when restoring state, if a VPA *is* + * registered, we need to set that up first. If not, we need to + * deregister the others before deregistering the master VPA */ + assert(env->vpa_addr || !(env->slb_shadow_addr || env->dtl_addr)); + + if (env->vpa_addr) { + reg.id = KVM_REG_PPC_VPA_ADDR; + reg.addr = (uintptr_t)&env->vpa_addr; + ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, ®); + if (ret < 0) { + dprintf("Unable to set VPA address to KVM: %s\n", strerror(errno)); + return ret; + } + } + + assert((uintptr_t)&env->slb_shadow_size + == ((uintptr_t)&env->slb_shadow_addr + 8)); + reg.id = KVM_REG_PPC_VPA_SLB; + reg.addr = (uintptr_t)&env->slb_shadow_addr; + ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, ®); + if (ret < 0) { + dprintf("Unable to set SLB shadow state to KVM: %s\n", strerror(errno)); + return ret; + } + + assert((uintptr_t)&env->dtl_size == ((uintptr_t)&env->dtl_addr + 8)); + reg.id = KVM_REG_PPC_VPA_DTL; + reg.addr = (uintptr_t)&env->dtl_addr; + ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, ®); + if (ret < 0) { + dprintf("Unable to set dispatch trace log state to KVM: %s\n", + strerror(errno)); + return ret; + } + + if (!env->vpa_addr) { + reg.id = KVM_REG_PPC_VPA_ADDR; + reg.addr = (uintptr_t)&env->vpa_addr; + ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, ®); + if (ret < 0) { + dprintf("Unable to set VPA address to KVM: %s\n", strerror(errno)); + return ret; + } + } + + return 0; +} +#endif /* TARGET_PPC64 */ + int kvm_arch_put_registers(CPUState *cs, int level) { PowerPCCPU *cpu = POWERPC_CPU(cs); @@ -752,6 +852,14 @@ int kvm_arch_put_registers(CPUState *cs, int level) kvm_put_one_spr(cs, id, i); } } + +#ifdef TARGET_PPC64 + if (cap_papr) { + if (kvm_put_vpa(cs) < 0) { + dprintf("Warning: Unable to set VPA information to KVM\n"); + } + } +#endif /* TARGET_PPC64 */ } return ret; @@ -953,6 +1061,14 @@ int kvm_arch_get_registers(CPUState *cs) kvm_get_one_spr(cs, id, i); } } + +#ifdef TARGET_PPC64 + if (cap_papr) { + if (kvm_get_vpa(cs) < 0) { + dprintf("Warning: Unable to get VPA information from KVM\n"); + } + } +#endif } return 0; @@ -1301,6 +1417,10 @@ void kvmppc_set_papr(PowerPCCPU *cpu) if (ret) { cpu_abort(env, "This KVM version does not support PAPR\n"); } + + /* Update the capability flag so we sync the right information + * with kvm */ + cap_papr = 1; } void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mpic_proxy) -- 1.7.10.4