From c723d4c15e224e9d058384eecd30559580836c7a Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Tue, 13 Dec 2022 22:40:56 +0000 Subject: [PATCH] hw/xen: Implement EVTCHNOP_bind_virq Add the array of virq ports to each vCPU so that we can deliver timers, debug ports, etc. Global virqs are allocated against vCPU 0 initially, but can be migrated to other vCPUs (when we implement that). The kernel needs to know about VIRQ_TIMER in order to accelerate timers, so tell it via KVM_XEN_VCPU_ATTR_TYPE_TIMER. Also save/restore the value of the singleshot timer across migration, as the kernel will handle the hypercalls automatically now. Signed-off-by: David Woodhouse Reviewed-by: Paul Durrant --- hw/i386/kvm/xen_evtchn.c | 85 ++++++++++++++++++++++++++++++++++++ hw/i386/kvm/xen_evtchn.h | 2 + include/sysemu/kvm_xen.h | 1 + target/i386/cpu.h | 4 ++ target/i386/kvm/xen-emu.c | 91 +++++++++++++++++++++++++++++++++++++++ target/i386/machine.c | 2 + 6 files changed, 185 insertions(+) diff --git a/hw/i386/kvm/xen_evtchn.c b/hw/i386/kvm/xen_evtchn.c index 54707f1f9f..a3202d39ab 100644 --- a/hw/i386/kvm/xen_evtchn.c +++ b/hw/i386/kvm/xen_evtchn.c @@ -244,6 +244,11 @@ static bool valid_port(evtchn_port_t port) } } +static bool valid_vcpu(uint32_t vcpu) +{ + return !!qemu_get_cpu(vcpu); +} + int xen_evtchn_status_op(struct evtchn_status *status) { XenEvtchnState *s = xen_evtchn_singleton; @@ -496,6 +501,43 @@ static void free_port(XenEvtchnState *s, evtchn_port_t port) clear_port_pending(s, port); } +static int allocate_port(XenEvtchnState *s, uint32_t vcpu, uint16_t type, + uint16_t val, evtchn_port_t *port) +{ + evtchn_port_t p = 1; + + for (p = 1; valid_port(p); p++) { + if (s->port_table[p].type == EVTCHNSTAT_closed) { + s->port_table[p].vcpu = vcpu; + s->port_table[p].type = type; + s->port_table[p].type_val = val; + + *port = p; + + if (s->nr_ports < p + 1) { + s->nr_ports = p + 1; + } + + return 0; + } + } + return -ENOSPC; +} + +static bool virq_is_global(uint32_t virq) +{ + switch (virq) { + case VIRQ_TIMER: + case VIRQ_DEBUG: + case VIRQ_XENOPROF: + case VIRQ_XENPMU: + return false; + + default: + return true; + } +} + static int close_port(XenEvtchnState *s, evtchn_port_t port) { XenEvtchnPort *p = &s->port_table[port]; @@ -504,6 +546,11 @@ static int close_port(XenEvtchnState *s, evtchn_port_t port) case EVTCHNSTAT_closed: return -ENOENT; + case EVTCHNSTAT_virq: + kvm_xen_set_vcpu_virq(virq_is_global(p->type_val) ? 0 : p->vcpu, + p->type_val, 0); + break; + default: break; } @@ -555,3 +602,41 @@ int xen_evtchn_unmask_op(struct evtchn_unmask *unmask) return ret; } + +int xen_evtchn_bind_virq_op(struct evtchn_bind_virq *virq) +{ + XenEvtchnState *s = xen_evtchn_singleton; + int ret; + + if (!s) { + return -ENOTSUP; + } + + if (virq->virq >= NR_VIRQS) { + return -EINVAL; + } + + /* Global VIRQ must be allocated on vCPU0 first */ + if (virq_is_global(virq->virq) && virq->vcpu != 0) { + return -EINVAL; + } + + if (!valid_vcpu(virq->vcpu)) { + return -ENOENT; + } + + qemu_mutex_lock(&s->port_lock); + + ret = allocate_port(s, virq->vcpu, EVTCHNSTAT_virq, virq->virq, + &virq->port); + if (!ret) { + ret = kvm_xen_set_vcpu_virq(virq->vcpu, virq->virq, virq->port); + if (ret) { + free_port(s, virq->port); + } + } + + qemu_mutex_unlock(&s->port_lock); + + return ret; +} diff --git a/hw/i386/kvm/xen_evtchn.h b/hw/i386/kvm/xen_evtchn.h index 69c6b0d743..0ea13dda3a 100644 --- a/hw/i386/kvm/xen_evtchn.h +++ b/hw/i386/kvm/xen_evtchn.h @@ -18,8 +18,10 @@ int xen_evtchn_set_callback_param(uint64_t param); struct evtchn_status; struct evtchn_close; struct evtchn_unmask; +struct evtchn_bind_virq; int xen_evtchn_status_op(struct evtchn_status *status); int xen_evtchn_close_op(struct evtchn_close *close); int xen_evtchn_unmask_op(struct evtchn_unmask *unmask); +int xen_evtchn_bind_virq_op(struct evtchn_bind_virq *virq); #endif /* QEMU_XEN_EVTCHN_H */ diff --git a/include/sysemu/kvm_xen.h b/include/sysemu/kvm_xen.h index 644c7d889c..fbb7414eb7 100644 --- a/include/sysemu/kvm_xen.h +++ b/include/sysemu/kvm_xen.h @@ -23,6 +23,7 @@ int kvm_xen_soft_reset(void); uint32_t kvm_xen_get_caps(void); void *kvm_xen_get_vcpu_info_hva(uint32_t vcpu_id); void kvm_xen_inject_vcpu_callback_vector(uint32_t vcpu_id, int type); +int kvm_xen_set_vcpu_virq(uint32_t vcpu_id, uint16_t virq, uint16_t port); #define kvm_xen_has_cap(cap) (!!(kvm_xen_get_caps() & \ KVM_XEN_HVM_CONFIG_ ## cap)) diff --git a/target/i386/cpu.h b/target/i386/cpu.h index 1c7603221d..4b70257db5 100644 --- a/target/i386/cpu.h +++ b/target/i386/cpu.h @@ -27,6 +27,8 @@ #include "qapi/qapi-types-common.h" #include "qemu/cpu-float.h" +#define XEN_NR_VIRQS 24 + /* The x86 has a strong memory model with some store-after-load re-ordering */ #define TCG_GUEST_DEFAULT_MO (TCG_MO_ALL & ~TCG_MO_ST_LD) @@ -1806,6 +1808,8 @@ typedef struct CPUArchState { uint64_t xen_vcpu_time_info_gpa; uint64_t xen_vcpu_runstate_gpa; uint8_t xen_vcpu_callback_vector; + uint16_t xen_virq[XEN_NR_VIRQS]; + uint64_t xen_singleshot_timer_ns; #endif #if defined(CONFIG_HVF) HVFX86LazyFlags hvf_lflags; diff --git a/target/i386/kvm/xen-emu.c b/target/i386/kvm/xen-emu.c index 884e1c9c11..e0417f3d13 100644 --- a/target/i386/kvm/xen-emu.c +++ b/target/i386/kvm/xen-emu.c @@ -355,6 +355,53 @@ void kvm_xen_inject_vcpu_callback_vector(uint32_t vcpu_id, int type) } } +static int kvm_xen_set_vcpu_timer(CPUState *cs) +{ + X86CPU *cpu = X86_CPU(cs); + CPUX86State *env = &cpu->env; + + struct kvm_xen_vcpu_attr va = { + .type = KVM_XEN_VCPU_ATTR_TYPE_TIMER, + .u.timer.port = env->xen_virq[VIRQ_TIMER], + .u.timer.priority = KVM_IRQ_ROUTING_XEN_EVTCHN_PRIO_2LEVEL, + .u.timer.expires_ns = env->xen_singleshot_timer_ns, + }; + + return kvm_vcpu_ioctl(cs, KVM_XEN_VCPU_SET_ATTR, &va); +} + +static void do_set_vcpu_timer_virq(CPUState *cs, run_on_cpu_data data) +{ + kvm_xen_set_vcpu_timer(cs); +} + +int kvm_xen_set_vcpu_virq(uint32_t vcpu_id, uint16_t virq, uint16_t port) +{ + CPUState *cs = qemu_get_cpu(vcpu_id); + + if (!cs) { + return -ENOENT; + } + + /* cpu.h doesn't include the actual Xen header. */ + qemu_build_assert(NR_VIRQS == XEN_NR_VIRQS); + + if (virq >= NR_VIRQS) { + return -EINVAL; + } + + if (port && X86_CPU(cs)->env.xen_virq[virq]) { + return -EEXIST; + } + + X86_CPU(cs)->env.xen_virq[virq] = port; + if (virq == VIRQ_TIMER && kvm_xen_has_cap(EVTCHN_SEND)) { + async_run_on_cpu(cs, do_set_vcpu_timer_virq, + RUN_ON_CPU_HOST_INT(port)); + } + return 0; +} + static void do_set_vcpu_time_info_gpa(CPUState *cs, run_on_cpu_data data) { X86CPU *cpu = X86_CPU(cs); @@ -387,6 +434,8 @@ static void do_vcpu_soft_reset(CPUState *cs, run_on_cpu_data data) env->xen_vcpu_time_info_gpa = INVALID_GPA; env->xen_vcpu_runstate_gpa = INVALID_GPA; env->xen_vcpu_callback_vector = 0; + env->xen_singleshot_timer_ns = 0; + memset(env->xen_virq, 0, sizeof(env->xen_virq)); set_vcpu_info(cs, INVALID_GPA); kvm_xen_set_vcpu_attr(cs, KVM_XEN_VCPU_ATTR_TYPE_VCPU_TIME_INFO, @@ -395,6 +444,7 @@ static void do_vcpu_soft_reset(CPUState *cs, run_on_cpu_data data) INVALID_GPA); if (kvm_xen_has_cap(EVTCHN_SEND)) { kvm_xen_set_vcpu_callback_vector(cs); + kvm_xen_set_vcpu_timer(cs); } } @@ -829,6 +879,21 @@ static bool kvm_xen_hcall_evtchn_op(struct kvm_xen_exit *exit, X86CPU *cpu, err = xen_evtchn_unmask_op(&unmask); break; } + case EVTCHNOP_bind_virq: { + struct evtchn_bind_virq virq; + + qemu_build_assert(sizeof(virq) == 12); + if (kvm_copy_from_gva(cs, arg, &virq, sizeof(virq))) { + err = -EFAULT; + break; + } + + err = xen_evtchn_bind_virq_op(&virq); + if (!err && kvm_copy_to_gva(cs, arg, &virq, sizeof(virq))) { + err = -EFAULT; + } + break; + } default: return false; } @@ -1060,6 +1125,12 @@ int kvm_put_xen_state(CPUState *cs) } } + if (env->xen_virq[VIRQ_TIMER]) { + ret = kvm_xen_set_vcpu_timer(cs); + if (ret < 0) { + return ret; + } + } return 0; } @@ -1068,6 +1139,7 @@ int kvm_get_xen_state(CPUState *cs) X86CPU *cpu = X86_CPU(cs); CPUX86State *env = &cpu->env; uint64_t gpa; + int ret; /* * The kernel does not mark vcpu_info as dirty when it delivers interrupts @@ -1090,5 +1162,24 @@ int kvm_get_xen_state(CPUState *cs) } } + if (!kvm_xen_has_cap(EVTCHN_SEND)) { + return 0; + } + + /* + * If the kernel is accelerating timers, read out the current value of the + * singleshot timer deadline. + */ + if (env->xen_virq[VIRQ_TIMER]) { + struct kvm_xen_vcpu_attr va = { + .type = KVM_XEN_VCPU_ATTR_TYPE_TIMER, + }; + ret = kvm_vcpu_ioctl(cs, KVM_XEN_VCPU_GET_ATTR, &va); + if (ret < 0) { + return ret; + } + env->xen_singleshot_timer_ns = va.u.timer.expires_ns; + } + return 0; } diff --git a/target/i386/machine.c b/target/i386/machine.c index a4874eda90..603a1077e3 100644 --- a/target/i386/machine.c +++ b/target/i386/machine.c @@ -1275,6 +1275,8 @@ static const VMStateDescription vmstate_xen_vcpu = { VMSTATE_UINT64(env.xen_vcpu_time_info_gpa, X86CPU), VMSTATE_UINT64(env.xen_vcpu_runstate_gpa, X86CPU), VMSTATE_UINT8(env.xen_vcpu_callback_vector, X86CPU), + VMSTATE_UINT16_ARRAY(env.xen_virq, X86CPU, XEN_NR_VIRQS), + VMSTATE_UINT64(env.xen_singleshot_timer_ns, X86CPU), VMSTATE_END_OF_LIST() } };