This is incomplete, because the region is unref-ed immediately. It would not be safe against memory hot-unplug. Otherwise it works.
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> --- hw/virtio/dataplane/Makefile.objs | 2 +- hw/virtio/dataplane/hostmem.c | 183 --------------------------------- hw/virtio/dataplane/vring.c | 56 ++++++++-- include/hw/virtio/dataplane/hostmem.h | 58 ----------- include/hw/virtio/dataplane/vring.h | 3 +- 5 files changed, 48 insertions(+), 254 deletions(-) delete mode 100644 hw/virtio/dataplane/hostmem.c delete mode 100644 include/hw/virtio/dataplane/hostmem.h diff --git a/hw/virtio/dataplane/Makefile.objs b/hw/virtio/dataplane/Makefile.objs index a91bf33..9a8cfc0 100644 --- a/hw/virtio/dataplane/Makefile.objs +++ b/hw/virtio/dataplane/Makefile.objs @@ -1 +1 @@ -common-obj-y += hostmem.o vring.o +common-obj-y += vring.o diff --git a/hw/virtio/dataplane/hostmem.c b/hw/virtio/dataplane/hostmem.c deleted file mode 100644 index 66829bb..0000000 --- a/hw/virtio/dataplane/hostmem.c +++ /dev/null @@ -1,183 +0,0 @@ -/* - * Thread-safe guest to host memory mapping - * - * Copyright 2012 Red Hat, Inc. and/or its affiliates - * - * Authors: - * Stefan Hajnoczi <stefa...@redhat.com> - * - * This work is licensed under the terms of the GNU GPL, version 2 or later. - * See the COPYING file in the top-level directory. - * - */ - -#include "exec/address-spaces.h" -#include "hw/virtio/dataplane/hostmem.h" - -static int hostmem_lookup_cmp(const void *phys_, const void *region_) -{ - hwaddr phys = *(const hwaddr *)phys_; - const HostMemRegion *region = region_; - - if (phys < region->guest_addr) { - return -1; - } else if (phys >= region->guest_addr + region->size) { - return 1; - } else { - return 0; - } -} - -/** - * Map guest physical address to host pointer - */ -void *hostmem_lookup(HostMem *hostmem, hwaddr phys, hwaddr len, bool is_write) -{ - HostMemRegion *region; - void *host_addr = NULL; - hwaddr offset_within_region; - - qemu_mutex_lock(&hostmem->current_regions_lock); - region = bsearch(&phys, hostmem->current_regions, - hostmem->num_current_regions, - sizeof(hostmem->current_regions[0]), - hostmem_lookup_cmp); - if (!region) { - goto out; - } - if (is_write && region->readonly) { - goto out; - } - offset_within_region = phys - region->guest_addr; - if (len <= region->size - offset_within_region) { - host_addr = region->host_addr + offset_within_region; - } -out: - qemu_mutex_unlock(&hostmem->current_regions_lock); - - return host_addr; -} - -/** - * Install new regions list - */ -static void hostmem_listener_commit(MemoryListener *listener) -{ - HostMem *hostmem = container_of(listener, HostMem, listener); - int i; - - qemu_mutex_lock(&hostmem->current_regions_lock); - for (i = 0; i < hostmem->num_current_regions; i++) { - memory_region_unref(hostmem->current_regions[i].mr); - } - g_free(hostmem->current_regions); - hostmem->current_regions = hostmem->new_regions; - hostmem->num_current_regions = hostmem->num_new_regions; - qemu_mutex_unlock(&hostmem->current_regions_lock); - - /* Reset new regions list */ - hostmem->new_regions = NULL; - hostmem->num_new_regions = 0; -} - -/** - * Add a MemoryRegionSection to the new regions list - */ -static void hostmem_append_new_region(HostMem *hostmem, - MemoryRegionSection *section) -{ - void *ram_ptr = memory_region_get_ram_ptr(section->mr); - size_t num = hostmem->num_new_regions; - size_t new_size = (num + 1) * sizeof(hostmem->new_regions[0]); - - hostmem->new_regions = g_realloc(hostmem->new_regions, new_size); - hostmem->new_regions[num] = (HostMemRegion){ - .host_addr = ram_ptr + section->offset_within_region, - .guest_addr = section->offset_within_address_space, - .size = section->size, - .readonly = section->readonly, - .mr = section->mr, - }; - hostmem->num_new_regions++; - - memory_region_ref(section->mr); -} - -static void hostmem_listener_append_region(MemoryListener *listener, - MemoryRegionSection *section) -{ - HostMem *hostmem = container_of(listener, HostMem, listener); - - /* Ignore non-RAM regions, we may not be able to map them */ - if (!memory_region_is_ram(section->mr)) { - return; - } - - /* Ignore regions with dirty logging, we cannot mark them dirty */ - if (memory_region_is_logging(section->mr)) { - return; - } - - hostmem_append_new_region(hostmem, section); -} - -/* We don't implement most MemoryListener callbacks, use these nop stubs */ -static void hostmem_listener_dummy(MemoryListener *listener) -{ -} - -static void hostmem_listener_section_dummy(MemoryListener *listener, - MemoryRegionSection *section) -{ -} - -static void hostmem_listener_eventfd_dummy(MemoryListener *listener, - MemoryRegionSection *section, - bool match_data, uint64_t data, - EventNotifier *e) -{ -} - -static void hostmem_listener_coalesced_mmio_dummy(MemoryListener *listener, - MemoryRegionSection *section, - hwaddr addr, hwaddr len) -{ -} - -void hostmem_init(HostMem *hostmem) -{ - memset(hostmem, 0, sizeof(*hostmem)); - - qemu_mutex_init(&hostmem->current_regions_lock); - - hostmem->listener = (MemoryListener){ - .begin = hostmem_listener_dummy, - .commit = hostmem_listener_commit, - .region_add = hostmem_listener_append_region, - .region_del = hostmem_listener_section_dummy, - .region_nop = hostmem_listener_append_region, - .log_start = hostmem_listener_section_dummy, - .log_stop = hostmem_listener_section_dummy, - .log_sync = hostmem_listener_section_dummy, - .log_global_start = hostmem_listener_dummy, - .log_global_stop = hostmem_listener_dummy, - .eventfd_add = hostmem_listener_eventfd_dummy, - .eventfd_del = hostmem_listener_eventfd_dummy, - .coalesced_mmio_add = hostmem_listener_coalesced_mmio_dummy, - .coalesced_mmio_del = hostmem_listener_coalesced_mmio_dummy, - .priority = 10, - }; - - memory_listener_register(&hostmem->listener, &address_space_memory); - if (hostmem->num_new_regions > 0) { - hostmem_listener_commit(&hostmem->listener); - } -} - -void hostmem_finalize(HostMem *hostmem) -{ - memory_listener_unregister(&hostmem->listener); - g_free(hostmem->new_regions); - g_free(hostmem->current_regions); - qemu_mutex_destroy(&hostmem->current_regions_lock); -} diff --git a/hw/virtio/dataplane/vring.c b/hw/virtio/dataplane/vring.c index e0d6e83..3b94279 100644 --- a/hw/virtio/dataplane/vring.c +++ b/hw/virtio/dataplane/vring.c @@ -15,9 +15,41 @@ */ #include "trace.h" +#include "hw/hw.h" +#include "exec/memory.h" +#include "exec/address-spaces.h" #include "hw/virtio/dataplane/vring.h" #include "qemu/error-report.h" +static void *vring_map(MemoryRegion **mr, hwaddr phys, hwaddr len, + bool is_write) +{ + MemoryRegionSection section = memory_region_find(get_system_memory(), phys, len); + + if (!section.mr || section.size < len) { + goto out; + } + if (is_write && section.readonly) { + goto out; + } + if (!memory_region_is_ram(section.mr)) { + goto out; + } + + /* Ignore regions with dirty logging, we cannot mark them dirty */ + if (memory_region_is_logging(section.mr)) { + goto out; + } + + *mr = section.mr; + return memory_region_get_ram_ptr(section.mr) + section.offset_within_region; + +out: + memory_region_unref(section.mr); + *mr = NULL; + return NULL; +} + /* Map the guest's vring to host memory */ bool vring_setup(Vring *vring, VirtIODevice *vdev, int n) { @@ -27,8 +59,7 @@ bool vring_setup(Vring *vring, VirtIODevice *vdev, int n) vring->broken = false; - hostmem_init(&vring->hostmem); - vring_ptr = hostmem_lookup(&vring->hostmem, vring_addr, vring_size, true); + vring_ptr = vring_map(&vring->mr, vring_addr, vring_size, true); if (!vring_ptr) { error_report("Failed to map vring " "addr %#" HWADDR_PRIx " size %" HWADDR_PRIu, @@ -51,7 +82,7 @@ bool vring_setup(Vring *vring, VirtIODevice *vdev, int n) void vring_teardown(Vring *vring) { - hostmem_finalize(&vring->hostmem); + memory_region_unref(vring->mr); } /* Disable guest->host notifies */ @@ -136,11 +167,13 @@ static int get_indirect(Vring *vring, do { struct vring_desc *desc_ptr; + MemoryRegion *mr; /* Translate indirect descriptor */ - desc_ptr = hostmem_lookup(&vring->hostmem, - indirect->addr + found * sizeof(desc), - sizeof(desc), false); + desc_ptr = vring_map(&mr, + indirect->addr + found * sizeof(desc), + sizeof(desc), false); + memory_region_unref(mr); /* TODO */ if (!desc_ptr) { error_report("Failed to map indirect descriptor " "addr %#" PRIx64 " len %zu", @@ -172,8 +205,9 @@ static int get_indirect(Vring *vring, return -ENOBUFS; } - iov->iov_base = hostmem_lookup(&vring->hostmem, desc.addr, desc.len, - desc.flags & VRING_DESC_F_WRITE); + iov->iov_base = vring_map(&mr, desc.addr, desc.len, + desc.flags & VRING_DESC_F_WRITE); + memory_region_unref(mr); /* TODO */ if (!iov->iov_base) { error_report("Failed to map indirect descriptor" "addr %#" PRIx64 " len %u", @@ -221,6 +255,7 @@ int vring_pop(VirtIODevice *vdev, Vring *vring, struct vring_desc desc; unsigned int i, head, found = 0, num = vring->vr.num; uint16_t avail_idx, last_avail_idx; + MemoryRegion *mr; /* If there was a fatal error then refuse operation */ if (vring->broken) { @@ -300,8 +335,9 @@ int vring_pop(VirtIODevice *vdev, Vring *vring, } /* TODO handle non-contiguous memory across region boundaries */ - iov->iov_base = hostmem_lookup(&vring->hostmem, desc.addr, desc.len, - desc.flags & VRING_DESC_F_WRITE); + iov->iov_base = vring_map(&mr, desc.addr, desc.len, + desc.flags & VRING_DESC_F_WRITE); + memory_region_unref(mr); /* TODO */ if (!iov->iov_base) { error_report("Failed to map vring desc addr %#" PRIx64 " len %u", (uint64_t)desc.addr, desc.len); diff --git a/include/hw/virtio/dataplane/hostmem.h b/include/hw/virtio/dataplane/hostmem.h deleted file mode 100644 index 2810f4b..0000000 --- a/include/hw/virtio/dataplane/hostmem.h +++ /dev/null @@ -1,58 +0,0 @@ -/* - * Thread-safe guest to host memory mapping - * - * Copyright 2012 Red Hat, Inc. and/or its affiliates - * - * Authors: - * Stefan Hajnoczi <stefa...@redhat.com> - * - * This work is licensed under the terms of the GNU GPL, version 2 or later. - * See the COPYING file in the top-level directory. - * - */ - -#ifndef HOSTMEM_H -#define HOSTMEM_H - -#include "exec/memory.h" -#include "qemu/thread.h" - -typedef struct { - MemoryRegion *mr; - void *host_addr; - hwaddr guest_addr; - uint64_t size; - bool readonly; -} HostMemRegion; - -typedef struct { - /* The listener is invoked when regions change and a new list of regions is - * built up completely before they are installed. - */ - MemoryListener listener; - HostMemRegion *new_regions; - size_t num_new_regions; - - /* Current regions are accessed from multiple threads either to lookup - * addresses or to install a new list of regions. The lock protects the - * pointer and the regions. - */ - QemuMutex current_regions_lock; - HostMemRegion *current_regions; - size_t num_current_regions; -} HostMem; - -void hostmem_init(HostMem *hostmem); -void hostmem_finalize(HostMem *hostmem); - -/** - * Map a guest physical address to a pointer - * - * Note that there is map/unmap mechanism here. The caller must ensure that - * mapped memory is no longer used across events like hot memory unplug. This - * can be done with other mechanisms like bdrv_drain_all() that quiesce - * in-flight I/O. - */ -void *hostmem_lookup(HostMem *hostmem, hwaddr phys, hwaddr len, bool is_write); - -#endif /* HOSTMEM_H */ diff --git a/include/hw/virtio/dataplane/vring.h b/include/hw/virtio/dataplane/vring.h index 9380cb5..caf5a41 100644 --- a/include/hw/virtio/dataplane/vring.h +++ b/include/hw/virtio/dataplane/vring.h @@ -19,11 +19,10 @@ #include <linux/virtio_ring.h> #include "qemu-common.h" -#include "hostmem.h" #include "hw/virtio/virtio.h" typedef struct { - HostMem hostmem; /* guest memory mapper */ + MemoryRegion *mr; /* memory region containing the vring */ struct vring vr; /* virtqueue vring mapped to host memory */ uint16_t last_avail_idx; /* last processed avail ring index */ uint16_t last_used_idx; /* last processed used ring index */ -- 1.7.1