| Message ID | 20180711205813.22346-1-danielhb413@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v1,1/1] scsi-disk: Block Device Characteristics emulation fix | expand |
On 11/07/2018 22:58, Daniel Henrique Barboza wrote: > The current BDC VPD page (page 0xb1) is too short. This can be > seen running sg_utils: > > $ sg_vpd --page=bdc /dev/sda > Block device characteristics VPD page (SBC): > Block device characteristics VPD page length too short=8 > > By the SCSI spec, the expected size of the SBC page is 0x40. > There is no telling how the guest will behave with a shorter > message - it can ignore it, or worse, make (wrong) > assumptions. > > This patch fixes the emulation by setting the size to 0x40. > This is the output of the previous sg_vpd command after > applying it: > > $ sg_vpd --page=bdc /dev/sda -v > inquiry cdb: 12 01 b1 00 fc 00 > Block device characteristics VPD page (SBC): > [PQual=0 Peripheral device type: disk] > Medium rotation rate is not reported > Product type: Not specified > WABEREQ=0 > WACEREQ=0 > Nominal form factor not reported > FUAB=0 > VBULS=0 > > To improve readability, this patch also adds the VBULS value > explictly and add comments on the existing fields we're > setting. > > Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com> Kevin kindly agreed to take this through the block tree, so Acked-by: Paolo Bonzini <pbonzini@redhat.com> Thanks, Paolo > --- > hw/scsi/scsi-disk.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c > index 32f3f96ff8..5ae7baa082 100644 > --- a/hw/scsi/scsi-disk.c > +++ b/hw/scsi/scsi-disk.c > @@ -775,11 +775,12 @@ int scsi_disk_emulate_vpd_page(SCSIRequest *req, uint8_t *outbuf) > } > case 0xb1: /* block device characteristics */ > { > - buflen = 8; > + buflen = 0x40; > outbuf[4] = (s->rotation_rate >> 8) & 0xff; > outbuf[5] = s->rotation_rate & 0xff; > - outbuf[6] = 0; > - outbuf[7] = 0; > + outbuf[6] = 0; /* PRODUCT TYPE */ > + outbuf[7] = 0; /* WABEREQ | WACEREQ | NOMINAL FORM FACTOR */ > + outbuf[8] = 0; /* VBULS */ > break; > } > case 0xb2: /* thin provisioning */ >
Am 12.07.2018 um 16:53 hat Paolo Bonzini geschrieben: > On 11/07/2018 22:58, Daniel Henrique Barboza wrote: > > The current BDC VPD page (page 0xb1) is too short. This can be > > seen running sg_utils: > > > > $ sg_vpd --page=bdc /dev/sda > > Block device characteristics VPD page (SBC): > > Block device characteristics VPD page length too short=8 > > > > By the SCSI spec, the expected size of the SBC page is 0x40. > > There is no telling how the guest will behave with a shorter > > message - it can ignore it, or worse, make (wrong) > > assumptions. > > > > This patch fixes the emulation by setting the size to 0x40. > > This is the output of the previous sg_vpd command after > > applying it: > > > > $ sg_vpd --page=bdc /dev/sda -v > > inquiry cdb: 12 01 b1 00 fc 00 > > Block device characteristics VPD page (SBC): > > [PQual=0 Peripheral device type: disk] > > Medium rotation rate is not reported > > Product type: Not specified > > WABEREQ=0 > > WACEREQ=0 > > Nominal form factor not reported > > FUAB=0 > > VBULS=0 > > > > To improve readability, this patch also adds the VBULS value > > explictly and add comments on the existing fields we're > > setting. > > > > Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com> > > Kevin kindly agreed to take this through the block tree, so > > Acked-by: Paolo Bonzini <pbonzini@redhat.com> Thanks, applied to the block branch. Kevin
diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c index 32f3f96ff8..5ae7baa082 100644 --- a/hw/scsi/scsi-disk.c +++ b/hw/scsi/scsi-disk.c @@ -775,11 +775,12 @@ int scsi_disk_emulate_vpd_page(SCSIRequest *req, uint8_t *outbuf) } case 0xb1: /* block device characteristics */ { - buflen = 8; + buflen = 0x40; outbuf[4] = (s->rotation_rate >> 8) & 0xff; outbuf[5] = s->rotation_rate & 0xff; - outbuf[6] = 0; - outbuf[7] = 0; + outbuf[6] = 0; /* PRODUCT TYPE */ + outbuf[7] = 0; /* WABEREQ | WACEREQ | NOMINAL FORM FACTOR */ + outbuf[8] = 0; /* VBULS */ break; } case 0xb2: /* thin provisioning */
The current BDC VPD page (page 0xb1) is too short. This can be seen running sg_utils: $ sg_vpd --page=bdc /dev/sda Block device characteristics VPD page (SBC): Block device characteristics VPD page length too short=8 By the SCSI spec, the expected size of the SBC page is 0x40. There is no telling how the guest will behave with a shorter message - it can ignore it, or worse, make (wrong) assumptions. This patch fixes the emulation by setting the size to 0x40. This is the output of the previous sg_vpd command after applying it: $ sg_vpd --page=bdc /dev/sda -v inquiry cdb: 12 01 b1 00 fc 00 Block device characteristics VPD page (SBC): [PQual=0 Peripheral device type: disk] Medium rotation rate is not reported Product type: Not specified WABEREQ=0 WACEREQ=0 Nominal form factor not reported FUAB=0 VBULS=0 To improve readability, this patch also adds the VBULS value explictly and add comments on the existing fields we're setting. Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com> --- hw/scsi/scsi-disk.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)