| Message ID | 34e287d0a8d585f104bdd06681b32fc93e8746c7.1639549843.git.jag.raman@oracle.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | vfio-user server in QEMU | expand |
On Wed, Dec 15, 2021 at 10:35:32AM -0500, Jagannathan Raman wrote: > 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> > --- > hw/remote/vfio-user-obj.c | 45 +++++++++++++++++++++++++++++++++++++++ > hw/remote/trace-events | 2 ++ > 2 files changed, 47 insertions(+) > > diff --git a/hw/remote/vfio-user-obj.c b/hw/remote/vfio-user-obj.c > index a01a0ad185..c6d0c675b7 100644 > --- a/hw/remote/vfio-user-obj.c > +++ b/hw/remote/vfio-user-obj.c > @@ -43,6 +43,7 @@ > #include "qapi/qapi-visit-sockets.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" > @@ -174,6 +175,39 @@ 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; > + > + 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 > @@ -244,6 +278,17 @@ static void vfu_object_init_ctx(VfuObject *o, Error **errp) > goto fail; > } > > + 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); Thanos or John: QEMU's pci_host_config_read/write_common() works with host-endian values. I don't know which endianness libvfio-user's region callbacks expect. Does this patch look endian-safe to you (e.g. will it work on a big-endian host)? Thanks, Stefan
On Thu, Dec 16, 2021 at 11:30:20AM +0000, Stefan Hajnoczi wrote: > > + 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); > > Thanos or John: QEMU's pci_host_config_read/write_common() works with > host-endian values. I don't know which endianness libvfio-user's region > callbacks expect. Does this patch look endian-safe to you (e.g. will it > work on a big-endian host)? https://github.com/nutanix/libvfio-user/issues/615 regards john
On Thu, Dec 16, 2021 at 11:47:40AM +0000, John Levon wrote: > On Thu, Dec 16, 2021 at 11:30:20AM +0000, Stefan Hajnoczi wrote: > > > > + 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); > > > > Thanos or John: QEMU's pci_host_config_read/write_common() works with > > host-endian values. I don't know which endianness libvfio-user's region > > callbacks expect. Does this patch look endian-safe to you (e.g. will it > > work on a big-endian host)? > > https://github.com/nutanix/libvfio-user/issues/615 Thanks! Stefan
diff --git a/hw/remote/vfio-user-obj.c b/hw/remote/vfio-user-obj.c index a01a0ad185..c6d0c675b7 100644 --- a/hw/remote/vfio-user-obj.c +++ b/hw/remote/vfio-user-obj.c @@ -43,6 +43,7 @@ #include "qapi/qapi-visit-sockets.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" @@ -174,6 +175,39 @@ 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; + + 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 @@ -244,6 +278,17 @@ static void vfu_object_init_ctx(VfuObject *o, Error **errp) goto fail; } + 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", diff --git a/hw/remote/trace-events b/hw/remote/trace-events index 7da12f0d96..2ef7884346 100644 --- a/hw/remote/trace-events +++ b/hw/remote/trace-events @@ -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"