On 16/02/2022 11:24, Jon Doron wrote:
> SynIc can be enabled regardless of the SControl mechanisim which can
> register a GSI for a given SintRoute.
>
> This behaviour can achived by setting enabling SIMP and then the guest
> will poll on the message slot.
>
> Once there is another message pending the host will set the message slot
> with the pending flag.
> When the guest polls from the message slot, in case the pending flag is
> set it will write to the HV_X64_MSR_EOM indicating it has cleared the
> slot and we can try and push our message again.
>
> Signed-off-by: Jon Doron <ari...@gmail.com>
> ---
> hw/hyperv/hyperv.c | 109 +++++++++++++++++++++++++++++++--------------
> 1 file changed, 76 insertions(+), 33 deletions(-)
>
> diff --git a/hw/hyperv/hyperv.c b/hw/hyperv/hyperv.c
> index cb1074f234..aaba6b4901 100644
> --- a/hw/hyperv/hyperv.c
> +++ b/hw/hyperv/hyperv.c
> @@ -27,13 +27,16 @@ struct SynICState {
>
> CPUState *cs;
>
> - bool enabled;
> + bool sctl_enabled;
> hwaddr msg_page_addr;
> hwaddr event_page_addr;
> MemoryRegion msg_page_mr;
> MemoryRegion event_page_mr;
> struct hyperv_message_page *msg_page;
> struct hyperv_event_flags_page *event_page;
> +
> + QemuMutex sint_routes_mutex;
> + QLIST_HEAD(, HvSintRoute) sint_routes;
> };
>
> #define TYPE_SYNIC "hyperv-synic"
> @@ -51,11 +54,11 @@ static SynICState *get_synic(CPUState *cs)
> return SYNIC(object_resolve_path_component(OBJECT(cs), "synic"));
> }
>
> -static void synic_update(SynICState *synic, bool enable,
> +static void synic_update(SynICState *synic, bool sctl_enable,
> hwaddr msg_page_addr, hwaddr event_page_addr)
> {
>
> - synic->enabled = enable;
> + synic->sctl_enabled = sctl_enable;
> if (synic->msg_page_addr != msg_page_addr) {
> if (synic->msg_page_addr) {
> memory_region_del_subregion(get_system_memory(),
> @@ -80,7 +83,7 @@ static void synic_update(SynICState *synic, bool enable,
> }
> }
>
> -void hyperv_synic_update(CPUState *cs, bool enable,
> +void hyperv_synic_update(CPUState *cs, bool sctl_enable,
> hwaddr msg_page_addr, hwaddr event_page_addr)
> {
> SynICState *synic = get_synic(cs);
> @@ -89,7 +92,7 @@ void hyperv_synic_update(CPUState *cs, bool enable,
> return;
> }
>
> - synic_update(synic, enable, msg_page_addr, event_page_addr);
> + synic_update(synic, sctl_enable, msg_page_addr, event_page_addr);
> }
>
> static void synic_realize(DeviceState *dev, Error **errp)
> @@ -110,16 +113,20 @@ static void synic_realize(DeviceState *dev, Error
> **errp)
> sizeof(*synic->event_page), &error_abort);
> synic->msg_page = memory_region_get_ram_ptr(&synic->msg_page_mr);
> synic->event_page = memory_region_get_ram_ptr(&synic->event_page_mr);
> + qemu_mutex_init(&synic->sint_routes_mutex);
> + QLIST_INIT(&synic->sint_routes);
>
> g_free(msgp_name);
> g_free(eventp_name);
> }
> +
> static void synic_reset(DeviceState *dev)
> {
> SynICState *synic = SYNIC(dev);
> memset(synic->msg_page, 0, sizeof(*synic->msg_page));
> memset(synic->event_page, 0, sizeof(*synic->event_page));
> synic_update(synic, false, 0, 0);
> + assert(QLIST_EMPTY(&synic->sint_routes));
> }
>
> static void synic_class_init(ObjectClass *klass, void *data)
> @@ -214,6 +221,7 @@ struct HvSintRoute {
> HvSintStagedMessage *staged_msg;
>
> unsigned refcount;
> + QLIST_ENTRY(HvSintRoute) link;
> };
>
> static CPUState *hyperv_find_vcpu(uint32_t vp_index)
> @@ -259,7 +267,7 @@ static void cpu_post_msg(CPUState *cs, run_on_cpu_data
> data)
>
> assert(staged_msg->state == HV_STAGED_MSG_BUSY);
>
> - if (!synic->enabled || !synic->msg_page_addr) {
> + if (!synic->msg_page_addr) {
> staged_msg->status = -ENXIO;
> goto posted;
> }
> @@ -343,7 +351,7 @@ int hyperv_set_event_flag(HvSintRoute *sint_route,
> unsigned eventno)
> if (eventno > HV_EVENT_FLAGS_COUNT) {
> return -EINVAL;
> }
> - if (!synic->enabled || !synic->event_page_addr) {
> + if (!synic->sctl_enabled || !synic->event_page_addr) {
> return -ENXIO;
> }
>
> @@ -364,11 +372,12 @@ int hyperv_set_event_flag(HvSintRoute *sint_route,
> unsigned eventno)
> HvSintRoute *hyperv_sint_route_new(uint32_t vp_index, uint32_t sint,
> HvSintMsgCb cb, void *cb_data)
> {
> - HvSintRoute *sint_route;
> - EventNotifier *ack_notifier;
> + HvSintRoute *sint_route = NULL;
> + EventNotifier *ack_notifier = NULL;
> int r, gsi;
> CPUState *cs;
> SynICState *synic;
> + bool ack_event_initialized = false;
>
> cs = hyperv_find_vcpu(vp_index);
> if (!cs) {
> @@ -381,57 +390,77 @@ HvSintRoute *hyperv_sint_route_new(uint32_t vp_index,
> uint32_t sint,
> }
>
> sint_route = g_new0(HvSintRoute, 1);
> - r = event_notifier_init(&sint_route->sint_set_notifier, false);
> - if (r) {
> - goto err;
> + if (!sint_route) {
> + return NULL;
> }
>
> + sint_route->synic = synic;
> + sint_route->sint = sint;
> + sint_route->refcount = 1;
>
> ack_notifier = cb ? &sint_route->sint_ack_notifier : NULL;
> if (ack_notifier) {
> sint_route->staged_msg = g_new0(HvSintStagedMessage, 1);
> + if (!sint_route->staged_msg) {
> + goto cleanup_err_sint;
> + }
> sint_route->staged_msg->cb = cb;
> sint_route->staged_msg->cb_data = cb_data;
>
> r = event_notifier_init(ack_notifier, false);
> if (r) {
> - goto err_sint_set_notifier;
> + goto cleanup_err_sint;
> }
> -
> event_notifier_set_handler(ack_notifier, sint_ack_handler);
> + ack_event_initialized = true;
> + }
> +
> + /* See if we are done or we need to setup a GSI for this SintRoute */
> + if (!synic->sctl_enabled) {
> + goto cleanup;
> + }
> +
> + /* We need to setup a GSI for this SintRoute */
> + r = event_notifier_init(&sint_route->sint_set_notifier, false);
> + if (r) {
> + goto cleanup_err_sint;
> }
>
> gsi = kvm_irqchip_add_hv_sint_route(kvm_state, vp_index, sint);
> if (gsi < 0) {
> - goto err_gsi;
> + goto cleanup_err_sint_notifier;
> }
>
> r = kvm_irqchip_add_irqfd_notifier_gsi(kvm_state,
> &sint_route->sint_set_notifier,
> ack_notifier, gsi);
> if (r) {
> - goto err_irqfd;
> + goto cleanup_err_irqfd;
> }
> sint_route->gsi = gsi;
> - sint_route->synic = synic;
> - sint_route->sint = sint;
> - sint_route->refcount = 1;
> -
> +cleanup:
> + qemu_mutex_lock(&synic->sint_routes_mutex);
> + QLIST_INSERT_HEAD_RCU(&synic->sint_routes, sint_route, link);
> + qemu_mutex_unlock(&synic->sint_routes_mutex);
> return sint_route;
>
> -err_irqfd:
> +cleanup_err_irqfd:
> kvm_irqchip_release_virq(kvm_state, gsi);
> -err_gsi:
> +
> +cleanup_err_sint_notifier:
> + event_notifier_cleanup(&sint_route->sint_set_notifier);
> +
> +cleanup_err_sint:
> if (ack_notifier) {
> - event_notifier_set_handler(ack_notifier, NULL);
> - event_notifier_cleanup(ack_notifier);
> + if (ack_event_initialized) {
> + event_notifier_set_handler(ack_notifier, NULL);
> + event_notifier_cleanup(ack_notifier);
> + }
> +
> g_free(sint_route->staged_msg);
> }
> -err_sint_set_notifier:
> - event_notifier_cleanup(&sint_route->sint_set_notifier);
> -err:
> - g_free(sint_route);
>
> + g_free(sint_route);
> return NULL;
> }
>
> @@ -442,6 +471,8 @@ void hyperv_sint_route_ref(HvSintRoute *sint_route)
>
> void hyperv_sint_route_unref(HvSintRoute *sint_route)
> {
> + SynICState *synic;
> +
> if (!sint_route) {
> return;
> }
> @@ -452,21 +483,33 @@ void hyperv_sint_route_unref(HvSintRoute *sint_route)
> return;
> }
>
> - kvm_irqchip_remove_irqfd_notifier_gsi(kvm_state,
> - &sint_route->sint_set_notifier,
> - sint_route->gsi);
> - kvm_irqchip_release_virq(kvm_state, sint_route->gsi);
> + synic = sint_route->synic;
> + qemu_mutex_lock(&synic->sint_routes_mutex);
> + QLIST_REMOVE_RCU(sint_route, link);
> + qemu_mutex_unlock(&synic->sint_routes_mutex);
> +
> + if (sint_route->gsi) {
> + kvm_irqchip_remove_irqfd_notifier_gsi(kvm_state,
> + &sint_route->sint_set_notifier,
> + sint_route->gsi);
> + kvm_irqchip_release_virq(kvm_state, sint_route->gsi);
> + event_notifier_cleanup(&sint_route->sint_set_notifier);
> + }
> +
> if (sint_route->staged_msg) {
> event_notifier_set_handler(&sint_route->sint_ack_notifier, NULL);
> event_notifier_cleanup(&sint_route->sint_ack_notifier);
> g_free(sint_route->staged_msg);
> }
> - event_notifier_cleanup(&sint_route->sint_set_notifier);
> g_free(sint_route);
> }
>
> int hyperv_sint_route_set_sint(HvSintRoute *sint_route)
> {
> + if (!sint_route->gsi) {
> + return 0;
> + }
> +
> return event_notifier_set(&sint_route->sint_set_notifier);
> }
>
>
Reviewed-by: Emanuele Giuseppe Esposito <eespo...@redhat.com>
