Commit 8d3bc0b7 authored by Roman Kagan's avatar Roman Kagan Committed by Paolo Bonzini
Browse files

hyperv: add support for KVM_HYPERV_EVENTFD 



When setting up a notifier for Hyper-V event connection, try to use the
KVM-assisted one first, and fall back to userspace handling of the
hypercall if the kernel doesn't provide the requested feature.

Signed-off-by: default avatarRoman Kagan <rkagan@virtuozzo.com>
Message-Id: <20180921082217.29481-9-rkagan@virtuozzo.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent e6ea9f45

hw/hyperv/hyperv.c

+26 −1
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
#include "exec/address-spaces.h"

#include "sysemu/kvm.h"

#include "qemu/bitops.h"

#include "qemu/error-report.h"

#include "qemu/queue.h"

#include "qemu/rcu.h"

#include "qemu/rcu_queue.h"
@@ -470,7 +471,7 @@ static void __attribute__((constructor)) hv_init(void) 
    qemu_mutex_init(&handlers_mutex);

}



int hyperv_set_event_flag_handler(uint32_t conn_id, EventNotifier *notifier)

static int set_event_flag_handler(uint32_t conn_id, EventNotifier *notifier)

{

    int ret;

    EventFlagHandler *handler;
@@ -503,6 +504,30 @@ unlock: 
    return ret;

}



static bool process_event_flags_userspace;



int hyperv_set_event_flag_handler(uint32_t conn_id, EventNotifier *notifier)

{

    if (!process_event_flags_userspace &&

        !kvm_check_extension(kvm_state, KVM_CAP_HYPERV_EVENTFD)) {

        process_event_flags_userspace = true;



        warn_report("Hyper-V event signaling is not supported by this kernel; "

                    "using slower userspace hypercall processing");

    }



    if (!process_event_flags_userspace) {

        struct kvm_hyperv_eventfd hvevfd = {

            .conn_id = conn_id,

            .fd = notifier ? event_notifier_get_fd(notifier) : -1,

            .flags = notifier ? 0 : KVM_HYPERV_EVENTFD_DEASSIGN,

        };



        return kvm_vm_ioctl(kvm_state, KVM_HYPERV_EVENTFD, &hvevfd);

    }

    return set_event_flag_handler(conn_id, notifier);

}



uint16_t hyperv_hcall_signal_event(uint64_t param, bool fast)

{

    uint16_t ret;