Re: [Qemu-devel] [PATCH v3] virtio-blk: set correct config size for the host driver
> -Original Message-
> From: Michael S. Tsirkin [mailto:m...@redhat.com]
> Sent: Tuesday, February 12, 2019 11:11 PM
> To: Liu, Changpeng
> Cc: qemu-devel@nongnu.org; stefa...@redhat.com; sgarz...@redhat.com;
> dgilb...@redhat.com; ldok...@redhat.com
> Subject: Re: [PATCH v3] virtio-blk: set correct config size for the host
> driver
>
> On Tue, Feb 12, 2019 at 11:19:49PM +0800, Changpeng Liu wrote:
> > Commit caa1ee43 "vhost-user-blk: add discard/write zeroes features
> > support" added fields to struct virtio_blk_config. This changes
> > the size of the config space and breaks migration from QEMU 3.1
> > and older:
> >
> > qemu-system-ppc64: get_pci_config_device: Bad config data: i=0x10 read: 41
> device: 1 cmask: ff wmask: 80 w1cmask:0
> > qemu-system-ppc64: Failed to load PCIDevice:config
> > qemu-system-ppc64: Failed to load virtio-blk:virtio
> > qemu-system-ppc64: error while loading state for instance 0x0 of device
> 'pci@8002000:01.0/virtio-blk'
> > qemu-system-ppc64: load of migration failed: Invalid argument
> >
> > Since virtio-blk doesn't support the "discard" and "write zeroes"
> > features, it shouldn't even expose the associated fields in the
> > config space actually. Just include all fields up to num_queues to
> > match QEMU 3.1 and older.
> >
> > Signed-off-by: Changpeng Liu
>
> OK almost.
>
> > ---
> > hw/block/virtio-blk.c | 14 ++
> > 1 file changed, 10 insertions(+), 4 deletions(-)
> >
> > diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
> > index 9a87b3b..0ff5315 100644
> > --- a/hw/block/virtio-blk.c
> > +++ b/hw/block/virtio-blk.c
> > @@ -28,6 +28,10 @@
> > #include "hw/virtio/virtio-bus.h"
> > #include "hw/virtio/virtio-access.h"
> >
> > +/* We don't support discard yet, hide associated config fields. */
> > +#define VIRTIO_BLK_CFG_SIZE offsetof(struct virtio_blk_config, \
> > + max_discard_sectors)
> > +
> > static void virtio_blk_init_request(VirtIOBlock *s, VirtQueue *vq,
> > VirtIOBlockReq *req)
> > {
> > @@ -761,7 +765,9 @@ static void virtio_blk_update_config(VirtIODevice
> *vdev, uint8_t *config)
> > blkcfg.alignment_offset = 0;
> > blkcfg.wce = blk_enable_write_cache(s->blk);
> > virtio_stw_p(vdev, _queues, s->conf.num_queues);
> > -memcpy(config, , sizeof(struct virtio_blk_config));
> > +memcpy(config, , VIRTIO_BLK_CFG_SIZE);
> > +QEMU_BUILD_BUG_ON(VIRTIO_BLK_CFG_SIZE > sizeof(struct
> virtio_blk_config));
> > +
>
> Oh probably sizeof blkcfg here, right?
> Also we don't need the empty line here.
Ok, removed the empty line and use sizeof(blkcfg) instead with v4.
>
> > }
> >
> > static void virtio_blk_set_config(VirtIODevice *vdev, const uint8_t
> > *config)
> > @@ -769,7 +775,8 @@ static void virtio_blk_set_config(VirtIODevice *vdev,
> const uint8_t *config)
> > VirtIOBlock *s = VIRTIO_BLK(vdev);
> > struct virtio_blk_config blkcfg;
> >
> > -memcpy(, config, sizeof(blkcfg));
> > +memcpy(, config, VIRTIO_BLK_CFG_SIZE);
> > +QEMU_BUILD_BUG_ON(VIRTIO_BLK_CFG_SIZE > sizeof(blkcfg));
> >
> > aio_context_acquire(blk_get_aio_context(s->blk));
> > blk_set_enable_write_cache(s->blk, blkcfg.wce != 0);
> > @@ -952,8 +959,7 @@ static void virtio_blk_device_realize(DeviceState *dev,
> Error **errp)
> > return;
> > }
> >
> > -virtio_init(vdev, "virtio-blk", VIRTIO_ID_BLOCK,
> > -sizeof(struct virtio_blk_config));
> > +virtio_init(vdev, "virtio-blk", VIRTIO_ID_BLOCK, VIRTIO_BLK_CFG_SIZE);
> >
> > s->blk = conf->conf.blk;
> > s->rq = NULL;
> > --
> > 1.9.3
Re: [Qemu-devel] [PATCH v3] virtio-blk: set correct config size for the host driver
On Tue, 12 Feb 2019 23:19:49 +0800
Changpeng Liu wrote:
> Commit caa1ee43 "vhost-user-blk: add discard/write zeroes features
> support" added fields to struct virtio_blk_config. This changes
> the size of the config space and breaks migration from QEMU 3.1
> and older:
>
> qemu-system-ppc64: get_pci_config_device: Bad config data: i=0x10 read: 41
> device: 1 cmask: ff wmask: 80 w1cmask:0
> qemu-system-ppc64: Failed to load PCIDevice:config
> qemu-system-ppc64: Failed to load virtio-blk:virtio
> qemu-system-ppc64: error while loading state for instance 0x0 of device
> 'pci@8002000:01.0/virtio-blk'
> qemu-system-ppc64: load of migration failed: Invalid argument
>
> Since virtio-blk doesn't support the "discard" and "write zeroes"
> features, it shouldn't even expose the associated fields in the
> config space actually. Just include all fields up to num_queues to
> match QEMU 3.1 and older.
>
> Signed-off-by: Changpeng Liu
> ---
Still looks good to me :)
Reviewed-by: Greg Kurz
Tested-by: Greg Kurz
> hw/block/virtio-blk.c | 14 ++
> 1 file changed, 10 insertions(+), 4 deletions(-)
>
> diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
> index 9a87b3b..0ff5315 100644
> --- a/hw/block/virtio-blk.c
> +++ b/hw/block/virtio-blk.c
> @@ -28,6 +28,10 @@
> #include "hw/virtio/virtio-bus.h"
> #include "hw/virtio/virtio-access.h"
>
> +/* We don't support discard yet, hide associated config fields. */
> +#define VIRTIO_BLK_CFG_SIZE offsetof(struct virtio_blk_config, \
> + max_discard_sectors)
> +
> static void virtio_blk_init_request(VirtIOBlock *s, VirtQueue *vq,
> VirtIOBlockReq *req)
> {
> @@ -761,7 +765,9 @@ static void virtio_blk_update_config(VirtIODevice *vdev,
> uint8_t *config)
> blkcfg.alignment_offset = 0;
> blkcfg.wce = blk_enable_write_cache(s->blk);
> virtio_stw_p(vdev, _queues, s->conf.num_queues);
> -memcpy(config, , sizeof(struct virtio_blk_config));
> +memcpy(config, , VIRTIO_BLK_CFG_SIZE);
> +QEMU_BUILD_BUG_ON(VIRTIO_BLK_CFG_SIZE > sizeof(struct
> virtio_blk_config));
> +
> }
>
> static void virtio_blk_set_config(VirtIODevice *vdev, const uint8_t *config)
> @@ -769,7 +775,8 @@ static void virtio_blk_set_config(VirtIODevice *vdev,
> const uint8_t *config)
> VirtIOBlock *s = VIRTIO_BLK(vdev);
> struct virtio_blk_config blkcfg;
>
> -memcpy(, config, sizeof(blkcfg));
> +memcpy(, config, VIRTIO_BLK_CFG_SIZE);
> +QEMU_BUILD_BUG_ON(VIRTIO_BLK_CFG_SIZE > sizeof(blkcfg));
>
> aio_context_acquire(blk_get_aio_context(s->blk));
> blk_set_enable_write_cache(s->blk, blkcfg.wce != 0);
> @@ -952,8 +959,7 @@ static void virtio_blk_device_realize(DeviceState *dev,
> Error **errp)
> return;
> }
>
> -virtio_init(vdev, "virtio-blk", VIRTIO_ID_BLOCK,
> -sizeof(struct virtio_blk_config));
> +virtio_init(vdev, "virtio-blk", VIRTIO_ID_BLOCK, VIRTIO_BLK_CFG_SIZE);
>
> s->blk = conf->conf.blk;
> s->rq = NULL;
Re: [Qemu-devel] [PATCH v3] virtio-blk: set correct config size for the host driver
On Tue, Feb 12, 2019 at 11:19:49PM +0800, Changpeng Liu wrote:
> Commit caa1ee43 "vhost-user-blk: add discard/write zeroes features
> support" added fields to struct virtio_blk_config. This changes
> the size of the config space and breaks migration from QEMU 3.1
> and older:
>
> qemu-system-ppc64: get_pci_config_device: Bad config data: i=0x10 read: 41
> device: 1 cmask: ff wmask: 80 w1cmask:0
> qemu-system-ppc64: Failed to load PCIDevice:config
> qemu-system-ppc64: Failed to load virtio-blk:virtio
> qemu-system-ppc64: error while loading state for instance 0x0 of device
> 'pci@8002000:01.0/virtio-blk'
> qemu-system-ppc64: load of migration failed: Invalid argument
>
> Since virtio-blk doesn't support the "discard" and "write zeroes"
> features, it shouldn't even expose the associated fields in the
> config space actually. Just include all fields up to num_queues to
> match QEMU 3.1 and older.
>
> Signed-off-by: Changpeng Liu
OK almost.
> ---
> hw/block/virtio-blk.c | 14 ++
> 1 file changed, 10 insertions(+), 4 deletions(-)
>
> diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
> index 9a87b3b..0ff5315 100644
> --- a/hw/block/virtio-blk.c
> +++ b/hw/block/virtio-blk.c
> @@ -28,6 +28,10 @@
> #include "hw/virtio/virtio-bus.h"
> #include "hw/virtio/virtio-access.h"
>
> +/* We don't support discard yet, hide associated config fields. */
> +#define VIRTIO_BLK_CFG_SIZE offsetof(struct virtio_blk_config, \
> + max_discard_sectors)
> +
> static void virtio_blk_init_request(VirtIOBlock *s, VirtQueue *vq,
> VirtIOBlockReq *req)
> {
> @@ -761,7 +765,9 @@ static void virtio_blk_update_config(VirtIODevice *vdev,
> uint8_t *config)
> blkcfg.alignment_offset = 0;
> blkcfg.wce = blk_enable_write_cache(s->blk);
> virtio_stw_p(vdev, _queues, s->conf.num_queues);
> -memcpy(config, , sizeof(struct virtio_blk_config));
> +memcpy(config, , VIRTIO_BLK_CFG_SIZE);
> +QEMU_BUILD_BUG_ON(VIRTIO_BLK_CFG_SIZE > sizeof(struct
> virtio_blk_config));
> +
Oh probably sizeof blkcfg here, right?
Also we don't need the empty line here.
> }
>
> static void virtio_blk_set_config(VirtIODevice *vdev, const uint8_t *config)
> @@ -769,7 +775,8 @@ static void virtio_blk_set_config(VirtIODevice *vdev,
> const uint8_t *config)
> VirtIOBlock *s = VIRTIO_BLK(vdev);
> struct virtio_blk_config blkcfg;
>
> -memcpy(, config, sizeof(blkcfg));
> +memcpy(, config, VIRTIO_BLK_CFG_SIZE);
> +QEMU_BUILD_BUG_ON(VIRTIO_BLK_CFG_SIZE > sizeof(blkcfg));
>
> aio_context_acquire(blk_get_aio_context(s->blk));
> blk_set_enable_write_cache(s->blk, blkcfg.wce != 0);
> @@ -952,8 +959,7 @@ static void virtio_blk_device_realize(DeviceState *dev,
> Error **errp)
> return;
> }
>
> -virtio_init(vdev, "virtio-blk", VIRTIO_ID_BLOCK,
> -sizeof(struct virtio_blk_config));
> +virtio_init(vdev, "virtio-blk", VIRTIO_ID_BLOCK, VIRTIO_BLK_CFG_SIZE);
>
> s->blk = conf->conf.blk;
> s->rq = NULL;
> --
> 1.9.3
[Qemu-devel] [PATCH v3] virtio-blk: set correct config size for the host driver
Commit caa1ee43 "vhost-user-blk: add discard/write zeroes features
support" added fields to struct virtio_blk_config. This changes
the size of the config space and breaks migration from QEMU 3.1
and older:
qemu-system-ppc64: get_pci_config_device: Bad config data: i=0x10 read: 41
device: 1 cmask: ff wmask: 80 w1cmask:0
qemu-system-ppc64: Failed to load PCIDevice:config
qemu-system-ppc64: Failed to load virtio-blk:virtio
qemu-system-ppc64: error while loading state for instance 0x0 of device
'pci@8002000:01.0/virtio-blk'
qemu-system-ppc64: load of migration failed: Invalid argument
Since virtio-blk doesn't support the "discard" and "write zeroes"
features, it shouldn't even expose the associated fields in the
config space actually. Just include all fields up to num_queues to
match QEMU 3.1 and older.
Signed-off-by: Changpeng Liu
---
hw/block/virtio-blk.c | 14 ++
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
index 9a87b3b..0ff5315 100644
--- a/hw/block/virtio-blk.c
+++ b/hw/block/virtio-blk.c
@@ -28,6 +28,10 @@
#include "hw/virtio/virtio-bus.h"
#include "hw/virtio/virtio-access.h"
+/* We don't support discard yet, hide associated config fields. */
+#define VIRTIO_BLK_CFG_SIZE offsetof(struct virtio_blk_config, \
+ max_discard_sectors)
+
static void virtio_blk_init_request(VirtIOBlock *s, VirtQueue *vq,
VirtIOBlockReq *req)
{
@@ -761,7 +765,9 @@ static void virtio_blk_update_config(VirtIODevice *vdev,
uint8_t *config)
blkcfg.alignment_offset = 0;
blkcfg.wce = blk_enable_write_cache(s->blk);
virtio_stw_p(vdev, _queues, s->conf.num_queues);
-memcpy(config, , sizeof(struct virtio_blk_config));
+memcpy(config, , VIRTIO_BLK_CFG_SIZE);
+QEMU_BUILD_BUG_ON(VIRTIO_BLK_CFG_SIZE > sizeof(struct virtio_blk_config));
+
}
static void virtio_blk_set_config(VirtIODevice *vdev, const uint8_t *config)
@@ -769,7 +775,8 @@ static void virtio_blk_set_config(VirtIODevice *vdev, const
uint8_t *config)
VirtIOBlock *s = VIRTIO_BLK(vdev);
struct virtio_blk_config blkcfg;
-memcpy(, config, sizeof(blkcfg));
+memcpy(, config, VIRTIO_BLK_CFG_SIZE);
+QEMU_BUILD_BUG_ON(VIRTIO_BLK_CFG_SIZE > sizeof(blkcfg));
aio_context_acquire(blk_get_aio_context(s->blk));
blk_set_enable_write_cache(s->blk, blkcfg.wce != 0);
@@ -952,8 +959,7 @@ static void virtio_blk_device_realize(DeviceState *dev,
Error **errp)
return;
}
-virtio_init(vdev, "virtio-blk", VIRTIO_ID_BLOCK,
-sizeof(struct virtio_blk_config));
+virtio_init(vdev, "virtio-blk", VIRTIO_ID_BLOCK, VIRTIO_BLK_CFG_SIZE);
s->blk = conf->conf.blk;
s->rq = NULL;
--
1.9.3
