vfio-user: handle PCI config space accesses

Define and register handlers for PCI config space accesses

Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: be9d2ccf9b1d24e50dcd9c23404dbf284142cec7.1655151679.git.jag.raman@oracle.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
Jagannathan Raman 2022-06-13 16:26:29 -04:00 committed by Stefan Hajnoczi
parent 9fb3fba149
commit 90072f29d6
2 changed files with 53 additions and 0 deletions

View File

@ -5,3 +5,5 @@ mpqemu_recv_io_error(int cmd, int size, int nfds) "failed to receive %d size %d,
# vfio-user-obj.c
vfu_prop(const char *prop, const char *val) "vfu: setting %s as %s"
vfu_cfg_read(uint32_t offset, uint32_t val) "vfu: cfg: 0x%u -> 0x%x"
vfu_cfg_write(uint32_t offset, uint32_t val) "vfu: cfg: 0x%u <- 0x%x"

View File

@ -46,6 +46,7 @@
#include "qapi/qapi-events-misc.h"
#include "qemu/notify.h"
#include "qemu/thread.h"
#include "qemu/main-loop.h"
#include "sysemu/sysemu.h"
#include "libvfio-user.h"
#include "hw/qdev-core.h"
@ -244,6 +245,45 @@ retry_attach:
qemu_set_fd_handler(o->vfu_poll_fd, vfu_object_ctx_run, NULL, o);
}
static ssize_t vfu_object_cfg_access(vfu_ctx_t *vfu_ctx, char * const buf,
size_t count, loff_t offset,
const bool is_write)
{
VfuObject *o = vfu_get_private(vfu_ctx);
uint32_t pci_access_width = sizeof(uint32_t);
size_t bytes = count;
uint32_t val = 0;
char *ptr = buf;
int len;
/*
* Writes to the BAR registers would trigger an update to the
* global Memory and IO AddressSpaces. But the remote device
* never uses the global AddressSpaces, therefore overlapping
* memory regions are not a problem
*/
while (bytes > 0) {
len = (bytes > pci_access_width) ? pci_access_width : bytes;
if (is_write) {
memcpy(&val, ptr, len);
pci_host_config_write_common(o->pci_dev, offset,
pci_config_size(o->pci_dev),
val, len);
trace_vfu_cfg_write(offset, val);
} else {
val = pci_host_config_read_common(o->pci_dev, offset,
pci_config_size(o->pci_dev), len);
memcpy(ptr, &val, len);
trace_vfu_cfg_read(offset, val);
}
offset += len;
ptr += len;
bytes -= len;
}
return count;
}
/*
* TYPE_VFU_OBJECT depends on the availability of the 'socket' and 'device'
* properties. It also depends on devices instantiated in QEMU. These
@ -336,6 +376,17 @@ static void vfu_object_init_ctx(VfuObject *o, Error **errp)
TYPE_VFU_OBJECT, o->device);
qdev_add_unplug_blocker(DEVICE(o->pci_dev), o->unplug_blocker);
ret = vfu_setup_region(o->vfu_ctx, VFU_PCI_DEV_CFG_REGION_IDX,
pci_config_size(o->pci_dev), &vfu_object_cfg_access,
VFU_REGION_FLAG_RW | VFU_REGION_FLAG_ALWAYS_CB,
NULL, 0, -1, 0);
if (ret < 0) {
error_setg(errp,
"vfu: Failed to setup config space handlers for %s- %s",
o->device, strerror(errno));
goto fail;
}
ret = vfu_realize_ctx(o->vfu_ctx);
if (ret < 0) {
error_setg(errp, "vfu: Failed to realize device %s- %s",