[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] Re: [PATCH] fix virtio_blk serial pci config breakage, v2
From: |
Michael S. Tsirkin |
Subject: |
[Qemu-devel] Re: [PATCH] fix virtio_blk serial pci config breakage, v2 |
Date: |
Mon, 5 Oct 2009 21:54:09 +0200 |
User-agent: |
Mutt/1.5.19 (2009-01-05) |
On Mon, Oct 05, 2009 at 11:47:51AM -0400, john cooper wrote:
> This is a re-work of the previous version where the
> associated data was being funneled through a free
> PCI BAR mapping. Here a request for the identify
> information results in a virtqueue command utilizing
> the scaffolding introduced by Rusty's recent patch.
>
> Signed-off-by: john cooper <address@hidden>
good stuff. A couple of comments below.
Also, what's going on with text alignment here?
> ---
>
>
> diff --git a/hw/virtio-blk.c b/hw/virtio-blk.c
> index dad4ef0..e754277 100644
> --- a/hw/virtio-blk.c
> +++ b/hw/virtio-blk.c
> @@ -25,6 +25,7 @@ typedef struct VirtIOBlock
> BlockDriverState *bs;
> VirtQueue *vq;
> void *rq;
> + uint16_t identify[VIRTIO_BLK_ID_LEN];
> } VirtIOBlock;
>
> static VirtIOBlock *to_virtio_blk(VirtIODevice *vdev)
> @@ -32,6 +33,48 @@ static VirtIOBlock *to_virtio_blk(VirtIODevice *vdev)
> return (VirtIOBlock *)vdev;
> }
>
> +/* store identify data in little endian format
> + */
> +static inline void put_le16(uint16_t *p, unsigned int v)
> +{
> + *p = cpu_to_le16(v);
> +}
> +
> +/* copy to *dst from *src, nul pad dst tail as needed to len bytes
> + */
> +static inline void padstr(char *dst, const char *src, int len)
> +{
> + while (len--)
> + *dst++ = *src ? *src++ : '\0';
> +}
> +
> +/* setup simulated identify data as appropriate for virtio block device
> + *
> + * ref: AT Attachment 8 - ATA/ATAPI Command Set (ATA8-ACS)
> + */
> +static inline void virtio_identify_template(VirtIOBlock *s)
> +{
> + uint16_t *p = s->identify;
> + uint64_t lba_sectors;
> +
> + memset(p, 0, sizeof(uint16_t) * VIRTIO_BLK_ID_LEN);
better as sizeof s->identity
> + put_le16(p + 0, 0x0); /* ATA device */
> + padstr((char *)(p + 23), QEMU_VERSION, 8); /* firmware revision */
QEMU version is currently a string like "0.11.50" which is exactly 8
bytes. What if someone makes it longer? padstr will not 0
terminate string, and only partial data will be there.
Maybe put compile assert here?
Also, identify is pre-initialized to 0, isn't it?
So just strcpy should be enough, here and elsewhere,
no need to roll our own padstr.
> + padstr((char *)(p + 27), "QEMU VIRT_BLK", 40); /* model# */
> + put_le16(p + 47, 0x80ff); /* max xfer 255 sectors
> */
> + put_le16(p + 49, 0x0b00); /* support
> IORDY/LBA/DMA */
> + put_le16(p + 59, 0x1ff); /* cur xfer 255 sectors
> */
> + put_le16(p + 80, 0x1f0); /* support ATA8/7/6/5/4
> */
> + put_le16(p + 81, 0x16);
> + put_le16(p + 82, 0x400);
> + put_le16(p + 83, 0x400);
> + bdrv_get_geometry(s->bs, &lba_sectors);
> + put_le16(p + 100, lba_sectors);
> + put_le16(p + 101, lba_sectors >> 16);
> + put_le16(p + 102, lba_sectors >> 32);
> + put_le16(p + 103, lba_sectors >> 48);
> +}
> +
> typedef struct VirtIOBlockReq
> {
> VirtIOBlock *dev;
> @@ -243,6 +286,11 @@ static void virtio_blk_handle_output(VirtIODevice *vdev,
> VirtQueue *vq)
>
> if (req->out->type & VIRTIO_BLK_T_SCSI_CMD) {
> virtio_blk_handle_scsi(req);
> + }
> + else if (req->out->type & VIRTIO_BLK_T_GET_ID) {
Pls put } and else on the same line
> + memcpy(req->elem.in_sg[0].iov_base, s->identify,
> + req->elem.in_sg[0].iov_len);
Is this safe? Can guest make iov_len bigger than size of s->identity?
> + virtio_blk_req_complete(req, VIRTIO_BLK_S_OK);
> } else if (req->out->type & VIRTIO_BLK_T_OUT) {
> qemu_iovec_init_external(&req->qiov, &req->elem.out_sg[1],
> req->elem.out_num - 1);
> @@ -304,6 +352,7 @@ static void virtio_blk_update_config(VirtIODevice *vdev,
> uint8_t *config)
>
> static uint32_t virtio_blk_get_features(VirtIODevice *vdev)
> {
> + VirtIOBlock *s = to_virtio_blk(vdev);
> uint32_t features = 0;
>
> features |= (1 << VIRTIO_BLK_F_SEG_MAX);
> @@ -311,6 +360,8 @@ static uint32_t virtio_blk_get_features(VirtIODevice
> *vdev)
> #ifdef __linux__
> features |= (1 << VIRTIO_BLK_F_SCSI);
> #endif
> + if (*(char *)&s->identify[VIRTIO_BLK_ID_SN])
> + features |= 1 << VIRTIO_BLK_F_GET_ID;
> return features;
> }
> @@ -360,7 +411,8 @@ void *virtio_blk_init(PCIBus *bus, BlockDriverState *bs)
> PCI_VENDOR_ID_REDHAT_QUMRANET,
> VIRTIO_ID_BLOCK,
> PCI_CLASS_STORAGE_OTHER, 0x00,
> - sizeof(struct virtio_blk_config),
> sizeof(VirtIOBlock));
> + sizeof(struct virtio_blk_config),
> + sizeof(VirtIOBlock));
> if (!s)
> return NULL;
>
> @@ -373,6 +425,10 @@ void *virtio_blk_init(PCIBus *bus, BlockDriverState *bs)
> bdrv_guess_geometry(s->bs, &cylinders, &heads, &secs);
> bdrv_set_geometry_hint(s->bs, cylinders, heads, secs);
>
> + virtio_identify_template(s);
> + strncpy((char *)&s->identify[VIRTIO_BLK_ID_SN],
> + (char *)drive_get_serial(bs), VIRTIO_BLK_ID_SN_BYTES);
This can silently truncate the serial, can't it?
Maybe check and error out?
> +
> s->vq = virtio_add_queue(&s->vdev, 128, virtio_blk_handle_output);
>
> qemu_add_vm_change_state_handler(virtio_blk_dma_restart_cb, s);
> diff --git a/hw/virtio-blk.h b/hw/virtio-blk.h
> index 5ef6c36..f508f20 100644
> --- a/hw/virtio-blk.h
> +++ b/hw/virtio-blk.h
> @@ -31,6 +31,12 @@
> #define VIRTIO_BLK_F_RO 5 /* Disk is read-only */
> #define VIRTIO_BLK_F_BLK_SIZE 6 /* Block size of disk is available*/
> #define VIRTIO_BLK_F_SCSI 7 /* Supports scsi command passthru */
> +#define _VIRTIO_BLK_F_IDENTIFY 8 /* obsolete */
Let's just put it in comment? It should not be used anywhere.
> +#define VIRTIO_BLK_F_GET_ID 10 /* ATA IDENTIFY supported */
> +
> +#define VIRTIO_BLK_ID_LEN 256 /* length of identify u16 array */
> +#define VIRTIO_BLK_ID_SN 10 /* start of char * serial# */
> +#define VIRTIO_BLK_ID_SN_BYTES 20 /* length in bytes of serial# */
>
> struct virtio_blk_config
> {
> @@ -48,6 +54,8 @@ struct virtio_blk_config
>
> /* This bit says it's a scsi command, not an actual read or write. */
> #define VIRTIO_BLK_T_SCSI_CMD 2
> +#define _VIRTIO_BLK_T_FLUSH 4
> +#define VIRTIO_BLK_T_GET_ID 8
>
> /* Barrier before this op. */
> #define VIRTIO_BLK_T_BARRIER 0x80000000
> diff --git a/hw/virtio.c b/hw/virtio.c
> index 78c7637..dc38f59 100644
> --- a/hw/virtio.c
> +++ b/hw/virtio.c
> @@ -44,6 +44,8 @@
> * a read-and-acknowledge. */
> #define VIRTIO_PCI_ISR 19
>
> +/* The remaining space is defined by each driver as the per-driver
> + * configuration space */
> #define VIRTIO_PCI_CONFIG 20
>
> /* Virtio ABI version, if we increment this, we break the guest driver. */
> diff --git a/sysemu.h b/sysemu.h
> index 1f45fd6..185b4e3 100644
> --- a/sysemu.h
> +++ b/sysemu.h
> @@ -141,6 +141,8 @@ typedef enum {
> BLOCK_ERR_STOP_ANY
> } BlockInterfaceErrorAction;
>
> +#define BLOCK_SERIAL_STRLEN 20
> +
> typedef struct DriveInfo {
> BlockDriverState *bdrv;
> BlockInterfaceType type;
> @@ -149,7 +151,7 @@ typedef struct DriveInfo {
> int used;
> int drive_opt_idx;
> BlockInterfaceErrorAction onerror;
> - char serial[21];
> + char serial[BLOCK_SERIAL_STRLEN + 1];
> } DriveInfo;
>
> #define MAX_IDE_DEVS 2
>
>
> --
> address@hidden
- [Qemu-devel] [PATCH] fix virtio_blk serial pci config breakage, v2, john cooper, 2009/10/05
- [Qemu-devel] Re: [PATCH] fix virtio_blk serial pci config breakage, v2,
Michael S. Tsirkin <=
- [Qemu-devel] Re: [PATCH] fix virtio_blk serial pci config breakage, v2, john cooper, 2009/10/07
- [Qemu-devel] Re: [PATCH] fix virtio_blk serial pci config breakage, v2, Anthony Liguori, 2009/10/07
- [Qemu-devel] Re: [PATCH] fix virtio_blk serial pci config breakage, v2, Michael S. Tsirkin, 2009/10/07
- [Qemu-devel] Re: [PATCH] fix virtio_blk serial pci config breakage, v2, Anthony Liguori, 2009/10/07
- [Qemu-devel] Re: [PATCH] fix virtio_blk serial pci config breakage, v2, john cooper, 2009/10/07
[Qemu-devel] Re: [PATCH] fix virtio_blk serial pci config breakage, v2, Michael S. Tsirkin, 2009/10/05
[Qemu-devel] Re: [PATCH] fix virtio_blk serial pci config breakage, v2, Anthony Liguori, 2009/10/06