Commit d9453c93 authored by Marc-André Lureau's avatar Marc-André Lureau
Browse files

ivshmem: add hostmem backend 



Instead of handling allocation, teach ivshmem to use a memory backend.
This allows to use hugetlbfs backed memory now.

Signed-off-by: default avatarMarc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: default avatarClaudio Fontana <claudio.fontana@huawei.com>
parent 2c04752c

hw/misc/ivshmem.c

+66 −18
Original line number Diff line number Diff line
@@ -26,6 +26,8 @@ 
#include "qemu/event_notifier.h"

#include "qemu/fifo8.h"

#include "sysemu/char.h"

#include "sysemu/hostmem.h"

#include "qapi/visitor.h"



#include "hw/misc/ivshmem.h"
@@ -57,6 +59,8 @@ 
#define IVSHMEM(obj) \

    OBJECT_CHECK(IVShmemState, (obj), TYPE_IVSHMEM)



#define IVSHMEM_MEMDEV_PROP "memdev"



typedef struct Peer {

    int nb_eventfds;

    EventNotifier *eventfds;
@@ -72,6 +76,7 @@ typedef struct IVShmemState { 
    PCIDevice parent_obj;

    /*< public >*/



    HostMemoryBackend *hostmem;

    uint32_t intrmask;

    uint32_t intrstatus;
@@ -673,7 +678,22 @@ static void pci_ivshmem_realize(PCIDevice *dev, Error **errp) 
    uint8_t attr = PCI_BASE_ADDRESS_SPACE_MEMORY |

        PCI_BASE_ADDRESS_MEM_PREFETCH;



    if (s->sizearg == NULL) {

    if (!!s->server_chr + !!s->shmobj + !!s->hostmem != 1) {

        error_setg(errp, "You must specify either a shmobj, a chardev"

                   " or a hostmem");

        return;

    }



    if (s->hostmem) {

        MemoryRegion *mr;



        if (s->sizearg) {

            g_warning("size argument ignored with hostmem");

        }



        mr = host_memory_backend_get_memory(s->hostmem, errp);

        s->ivshmem_size = memory_region_size(mr);

    } else if (s->sizearg == NULL) {

        s->ivshmem_size = 4 << 20; /* 4 MB default */

    } else {

        char *end;
@@ -731,7 +751,16 @@ static void pci_ivshmem_realize(PCIDevice *dev, Error **errp) 
        attr |= PCI_BASE_ADDRESS_MEM_TYPE_64;

    }



    if (s->server_chr != NULL) {

    if (s->hostmem != NULL) {

        MemoryRegion *mr;



        IVSHMEM_DPRINTF("using hostmem\n");



        mr = host_memory_backend_get_memory(MEMORY_BACKEND(s->hostmem), errp);

        vmstate_register_ram(mr, DEVICE(s));

        memory_region_add_subregion(&s->bar, 0, mr);

        pci_register_bar(PCI_DEVICE(s), 2, attr, &s->bar);

    } else if (s->server_chr != NULL) {

        if (strncmp(s->server_chr->filename, "unix:", 5)) {

            error_setg(errp, "chardev is not a unix client socket");

            return;
@@ -740,12 +769,6 @@ static void pci_ivshmem_realize(PCIDevice *dev, Error **errp) 
        /* if we get a UNIX socket as the parameter we will talk

         * to the ivshmem server to receive the memory region */



        if (s->shmobj != NULL) {

            error_setg(errp, "do not specify both 'chardev' "

                       "and 'shm' with ivshmem");

            return;

        }



        IVSHMEM_DPRINTF("using shared memory server (socket = %s)\n",

                        s->server_chr->filename);
@@ -769,11 +792,6 @@ static void pci_ivshmem_realize(PCIDevice *dev, Error **errp) 
        /* just map the file immediately, we're not using a server */

        int fd;



        if (s->shmobj == NULL) {

            error_setg(errp, "Must specify 'chardev' or 'shm' to ivshmem");

            return;

        }



        IVSHMEM_DPRINTF("using shm_open (shm object = %s)\n", s->shmobj);



        /* try opening with O_EXCL and if it succeeds zero the memory
@@ -813,16 +831,19 @@ static void pci_ivshmem_exit(PCIDevice *dev) 
    }



    if (memory_region_is_mapped(&s->ivshmem)) {

        if (!s->hostmem) {

            void *addr = memory_region_get_ram_ptr(&s->ivshmem);



        vmstate_unregister_ram(&s->ivshmem, DEVICE(dev));

        memory_region_del_subregion(&s->bar, &s->ivshmem);



            if (munmap(addr, s->ivshmem_size) == -1) {

            error_report("Failed to munmap shared memory %s", strerror(errno));

                error_report("Failed to munmap shared memory %s",

                             strerror(errno));

            }

        }



        vmstate_unregister_ram(&s->ivshmem, DEVICE(dev));

        memory_region_del_subregion(&s->bar, &s->ivshmem);

    }



    if (s->eventfd_chr) {

        for (i = 0; i < s->vectors; i++) {

            if (s->eventfd_chr[i]) {
@@ -963,10 +984,37 @@ static void ivshmem_class_init(ObjectClass *klass, void *data) 
    dc->desc = "Inter-VM shared memory";

}



static void ivshmem_check_memdev_is_busy(Object *obj, const char *name,

                                         Object *val, Error **errp)

{

    MemoryRegion *mr;



    mr = host_memory_backend_get_memory(MEMORY_BACKEND(val), errp);

    if (memory_region_is_mapped(mr)) {

        char *path = object_get_canonical_path_component(val);

        error_setg(errp, "can't use already busy memdev: %s", path);

        g_free(path);

    } else {

        qdev_prop_allow_set_link_before_realize(obj, name, val, errp);

    }

}



static void ivshmem_init(Object *obj)

{

    IVShmemState *s = IVSHMEM(obj);



    object_property_add_link(obj, IVSHMEM_MEMDEV_PROP, TYPE_MEMORY_BACKEND,

                             (Object **)&s->hostmem,

                             ivshmem_check_memdev_is_busy,

                             OBJ_PROP_LINK_UNREF_ON_RELEASE,

                             &error_abort);

}



static const TypeInfo ivshmem_info = {

    .name          = TYPE_IVSHMEM,

    .parent        = TYPE_PCI_DEVICE,

    .instance_size = sizeof(IVShmemState),

    .instance_init = ivshmem_init,

    .class_init    = ivshmem_class_init,

};

tests/ivshmem-test.c

+12 −0
Original line number Diff line number Diff line
@@ -386,6 +386,17 @@ static void test_ivshmem_hotplug(void) 
    g_free(opts);

}



static void test_ivshmem_memdev(void)

{

    IVState state;



    /* just for the sake of checking memory-backend property */

    setup_vm_cmd(&state, "-object memory-backend-ram,size=1M,id=mb1"

                 " -device ivshmem,memdev=mb1", false);



    qtest_quit(state.qtest);

}



static void cleanup(void)

{

    if (tmpshmem) {
@@ -470,6 +481,7 @@ int main(int argc, char **argv) 
    qtest_add_func("/ivshmem/pair", test_ivshmem_pair);

    qtest_add_func("/ivshmem/server", test_ivshmem_server);

    qtest_add_func("/ivshmem/hotplug", test_ivshmem_hotplug);

    qtest_add_func("/ivshmem/memdev", test_ivshmem_memdev);



    ret = g_test_run();