Commit 56a571d9 authored by Tetsuya Mukawa's avatar Tetsuya Mukawa Committed by Michael S. Tsirkin
Browse files

ivshmem: Store file descriptor for vhost-user negotiation 



If virtio-net driver allocates memory in ivshmem shared memory,
vhost-net will work correctly, but vhost-user will not work because
a fd of shared memory will not be sent to vhost-user backend.
This patch fixes ivshmem to store file descriptor of shared memory.
It will be used when vhost-user negotiates vhost-user backend.

Signed-off-by: default avatarTetsuya Mukawa <mukawa@igel.co.jp>
Reviewed-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 50e5ae4d

exec.c

+10 −0
Original line number Diff line number Diff line
@@ -1757,6 +1757,16 @@ int qemu_get_ram_fd(ram_addr_t addr) 
    return fd;

}



void qemu_set_ram_fd(ram_addr_t addr, int fd)

{

    RAMBlock *block;



    rcu_read_lock();

    block = qemu_get_ram_block(addr);

    block->fd = fd;

    rcu_read_unlock();

}



void *qemu_get_ram_block_host_ptr(ram_addr_t addr)

{

    RAMBlock *block;

hw/misc/ivshmem.c

+7 −2
Original line number Diff line number Diff line
@@ -29,6 +29,7 @@ 
#include "sysemu/char.h"

#include "sysemu/hostmem.h"

#include "qapi/visitor.h"

#include "exec/ram_addr.h"



#include "hw/misc/ivshmem.h"
@@ -422,6 +423,7 @@ static int create_shared_memory_BAR(IVShmemState *s, int fd, uint8_t attr, 


    memory_region_init_ram_ptr(&s->ivshmem, OBJECT(s), "ivshmem.bar2",

                               s->ivshmem_size, ptr);

    qemu_set_ram_fd(s->ivshmem.ram_addr, fd);

    vmstate_register_ram(&s->ivshmem, DEVICE(s));

    memory_region_add_subregion(&s->bar, 0, &s->ivshmem);
@@ -682,6 +684,7 @@ static void ivshmem_read(void *opaque, const uint8_t *buf, int size) 
        }

        memory_region_init_ram_ptr(&s->ivshmem, OBJECT(s),

                                   "ivshmem.bar2", s->ivshmem_size, map_ptr);

        qemu_set_ram_fd(s->ivshmem.ram_addr, incoming_fd);

        vmstate_register_ram(&s->ivshmem, DEVICE(s));



        IVSHMEM_DPRINTF("guest h/w addr = %p, size = %" PRIu64 "\n",
@@ -689,7 +692,6 @@ static void ivshmem_read(void *opaque, const uint8_t *buf, int size) 


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



        close(incoming_fd);

        return;

    }
@@ -991,7 +993,6 @@ static void pci_ivshmem_realize(PCIDevice *dev, Error **errp) 
        }



        create_shared_memory_BAR(s, fd, attr, errp);

        close(fd);

    }

}
@@ -1010,11 +1011,15 @@ 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);

            int fd;



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

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

                             strerror(errno));

            }



            if ((fd = qemu_get_ram_fd(s->ivshmem.ram_addr)) != -1)

                close(fd);

        }



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

include/exec/ram_addr.h

+1 −0
Original line number Diff line number Diff line
@@ -72,6 +72,7 @@ ram_addr_t qemu_ram_alloc_resizeable(ram_addr_t size, ram_addr_t max_size, 
                                                     void *host),

                                     MemoryRegion *mr, Error **errp);

int qemu_get_ram_fd(ram_addr_t addr);

void qemu_set_ram_fd(ram_addr_t addr, int fd);

void *qemu_get_ram_block_host_ptr(ram_addr_t addr);

void qemu_ram_free(ram_addr_t addr);