Commit af603142 authored by Nicholas Bellinger's avatar Nicholas Bellinger Committed by Paolo Bonzini
Browse files

vhost: Add vhost_commit callback for SeaBIOS ROM region re-mapping 



This patch follows MST's recommendation to move checks for
vhost_verify_ring_mappings() -> cpu_physical_memory_map() operations
from MemoryListener->region_[add,del]() -> vhost_set_memory() into
final MemoryListener->commit() -> vhost_commit() callback.

It addresses the case where virtio-scsi vq ioport RAM re-mapping
to read-only SeaBIOS ROM triggers a cpu_physical_memory_map()
NIL MemoryRegionSection pointer failure.

Also save vhost_dev->mem_changed_[start,end]_addr values in
vhost_set_memory() for final ranges_overlap checks.  (Thanks Paolo!)

Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Asias He <asias@redhat.com>
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
Acked-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 881d588a

hw/virtio/vhost.c

+38 −15
Original line number Diff line number Diff line
@@ -382,8 +382,6 @@ static void vhost_set_memory(MemoryListener *listener, 
    bool log_dirty = memory_region_is_logging(section->mr);

    int s = offsetof(struct vhost_memory, regions) +

        (dev->mem->nregions + 1) * sizeof dev->mem->regions[0];

    uint64_t log_size;

    int r;

    void *ram;



    dev->mem = g_realloc(dev->mem, s);
@@ -416,12 +414,47 @@ static void vhost_set_memory(MemoryListener *listener, 
        /* Remove old mapping for this memory, if any. */

        vhost_dev_unassign_memory(dev, start_addr, size);

    }

    dev->mem_changed_start_addr = MIN(dev->mem_changed_start_addr, start_addr);

    dev->mem_changed_end_addr = MAX(dev->mem_changed_end_addr, start_addr + size - 1);

    dev->memory_changed = true;

}



static bool vhost_section(MemoryRegionSection *section)

{

    return memory_region_is_ram(section->mr);

}



static void vhost_begin(MemoryListener *listener)

{

    struct vhost_dev *dev = container_of(listener, struct vhost_dev,

                                         memory_listener);

    dev->mem_changed_end_addr = 0;

    dev->mem_changed_start_addr = -1;

}



static void vhost_commit(MemoryListener *listener)

{

    struct vhost_dev *dev = container_of(listener, struct vhost_dev,

                                         memory_listener);

    hwaddr start_addr = 0;

    ram_addr_t size = 0;

    uint64_t log_size;

    int r;



    if (!dev->memory_changed) {

        return;

    }

    if (!dev->started) {

        return;

    }

    if (dev->mem_changed_start_addr > dev->mem_changed_end_addr) {

        return;

    }



    if (dev->started) {

        start_addr = dev->mem_changed_start_addr;

        size = dev->mem_changed_end_addr - dev->mem_changed_start_addr + 1;



        r = vhost_verify_ring_mappings(dev, start_addr, size);

        assert(r >= 0);

    }
@@ -429,6 +462,7 @@ static void vhost_set_memory(MemoryListener *listener, 
    if (!dev->log_enabled) {

        r = ioctl(dev->control, VHOST_SET_MEM_TABLE, dev->mem);

        assert(r >= 0);

        dev->memory_changed = false;

        return;

    }

    log_size = vhost_get_log_size(dev);
@@ -445,19 +479,7 @@ static void vhost_set_memory(MemoryListener *listener, 
    if (dev->log_size > log_size + VHOST_LOG_BUFFER) {

        vhost_dev_log_resize(dev, log_size);

    }

}



static bool vhost_section(MemoryRegionSection *section)

{

    return memory_region_is_ram(section->mr);

}



static void vhost_begin(MemoryListener *listener)

{

}



static void vhost_commit(MemoryListener *listener)

{

    dev->memory_changed = false;

}



static void vhost_region_add(MemoryListener *listener,
@@ -842,6 +864,7 @@ int vhost_dev_init(struct vhost_dev *hdev, int devfd, const char *devpath, 
    hdev->log_size = 0;

    hdev->log_enabled = false;

    hdev->started = false;

    hdev->memory_changed = false;

    memory_listener_register(&hdev->memory_listener, &address_space_memory);

    hdev->force = force;

    return 0;

include/hw/virtio/vhost.h

+3 −0
Original line number Diff line number Diff line
@@ -45,6 +45,9 @@ struct vhost_dev { 
    vhost_log_chunk_t *log;

    unsigned long long log_size;

    bool force;

    bool memory_changed;

    hwaddr mem_changed_start_addr;

    hwaddr mem_changed_end_addr;

};



int vhost_dev_init(struct vhost_dev *hdev, int devfd, const char *devpath,