qemu-patch-raspberry4/include/hw/scsi/scsi.h
Daniel Henrique Barboza a71c775b24 hw/scsi: add VPD Block Limits emulation
The VPD Block Limits Inquiry page is optional, allowing SCSI devices
to not implement it. This is the case for devices like the MegaRAID
SAS 9361-8i and Microsemi PM8069.

In case of SCSI passthrough, the response of this request is used by
the QEMU SCSI layer to set the max_io_sectors that the guest
device will support, based on the value of the max_sectors_kb that
the device has set in the host at that time. Without this response,
the guest kernel is free to assume any value of max_io_sectors
for the SCSI device. If this value is greater than the value from
the host, SCSI Sense errors will occur because the guest will send
read/write requests that are larger than the underlying host device
is configured to support. An example of this behavior can be seen
in [1].

A workaround is to set the max_sectors_kb host value back in the guest
kernel (a process that can be automated using rc.local startup scripts
and the like), but this has several drawbacks:

- it can be troublesome if the guest has many passthrough devices that
needs this tuning;

- if a change in max_sectors_kb is made in the host side, manual change
in the guests will also be required;

- during an OS install it is difficult, and sometimes not possible, to
go to a terminal and change the max_sectors_kb prior to the installation.
This means that the disk can't be used during the install process. The
easiest alternative here is to roll back to scsi-hd, install the guest
and then go back to SCSI passthrough when the installation is done and
max_sectors_kb can be set.

An easier way would be to QEMU handle the absence of the Block Limits
VPD device response, setting max_io_sectors accordingly and allowing
the guest to use the device without the hassle.

This patch adds emulation of the Block Limits VPD response for
SCSI passthrough devices of type TYPE_DISK that doesn't support
it. The following changes were made:

- scsi_handle_inquiry_reply will now check the available VPD
pages from the Inquiry EVPD reply. In case the device does not

- a new function called scsi_generic_set_vpd_bl_emulation,
that is called during device realize,  was created to set a
new flag 'needs_vpd_bl_emulation' of the device. This function
retrieves the Inquiry EVPD response of the device to check for
VPD BL support.

- scsi_handle_inquiry_reply will now check the available VPD
pages from the Inquiry EVPD reply in case the device needs
VPD BL emulation, adding the Block Limits page (0xb0) to
the list. This will make the guest kernel aware of the
support that we're now providing by emulation.

- a new function scsi_emulate_block_limits creates the
emulated Block Limits response. This function is called
inside scsi_read_complete in case the device requires
Block Limits VPD emulation and we detected a SCSI Sense
error in the VPD Block Limits reply that was issued
from the guest kernel to the device. This error is
expected: we're reporting support from our side, but
the device isn't aware of it.

With this patch, the guest now queries the Block Limits
page during the device configuration because it is being
advertised in the Supported Pages response. It will either
receive the Block Limits page from the hardware, if it supports
it, or will receive an emulated response from QEMU. At any rate,
the guest now has the information to set the max_sectors_kb
parameter accordingly, sparing the user of SCSI sense errors
that would happen without the emulated response and in the
absence of Block Limits support from the hardware.

[1] https://bugzilla.redhat.com/show_bug.cgi?id=1566195

Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1566195
Reported-by: Dac Nguyen <dacng@us.ibm.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20180627172432.11120-4-danielhb413@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-06-29 13:02:50 +02:00

199 lines
6.8 KiB
C

#ifndef QEMU_HW_SCSI_H
#define QEMU_HW_SCSI_H
#include "hw/qdev.h"
#include "hw/block/block.h"
#include "sysemu/sysemu.h"
#include "scsi/utils.h"
#include "qemu/notify.h"
#define MAX_SCSI_DEVS 255
typedef struct SCSIBus SCSIBus;
typedef struct SCSIBusInfo SCSIBusInfo;
typedef struct SCSIDevice SCSIDevice;
typedef struct SCSIRequest SCSIRequest;
typedef struct SCSIReqOps SCSIReqOps;
#define SCSI_SENSE_BUF_SIZE_OLD 96
#define SCSI_SENSE_BUF_SIZE 252
struct SCSIRequest {
SCSIBus *bus;
SCSIDevice *dev;
const SCSIReqOps *ops;
uint32_t refcount;
uint32_t tag;
uint32_t lun;
uint32_t status;
void *hba_private;
size_t resid;
SCSICommand cmd;
NotifierList cancel_notifiers;
/* Note:
* - fields before sense are initialized by scsi_req_alloc;
* - sense[] is uninitialized;
* - fields after sense are memset to 0 by scsi_req_alloc.
* */
uint8_t sense[SCSI_SENSE_BUF_SIZE];
uint32_t sense_len;
bool enqueued;
bool io_canceled;
bool retry;
bool dma_started;
BlockAIOCB *aiocb;
QEMUSGList *sg;
QTAILQ_ENTRY(SCSIRequest) next;
};
#define TYPE_SCSI_DEVICE "scsi-device"
#define SCSI_DEVICE(obj) \
OBJECT_CHECK(SCSIDevice, (obj), TYPE_SCSI_DEVICE)
#define SCSI_DEVICE_CLASS(klass) \
OBJECT_CLASS_CHECK(SCSIDeviceClass, (klass), TYPE_SCSI_DEVICE)
#define SCSI_DEVICE_GET_CLASS(obj) \
OBJECT_GET_CLASS(SCSIDeviceClass, (obj), TYPE_SCSI_DEVICE)
typedef struct SCSIDeviceClass {
DeviceClass parent_class;
void (*realize)(SCSIDevice *dev, Error **errp);
int (*parse_cdb)(SCSIDevice *dev, SCSICommand *cmd, uint8_t *buf,
void *hba_private);
SCSIRequest *(*alloc_req)(SCSIDevice *s, uint32_t tag, uint32_t lun,
uint8_t *buf, void *hba_private);
void (*unit_attention_reported)(SCSIDevice *s);
} SCSIDeviceClass;
struct SCSIDevice
{
DeviceState qdev;
VMChangeStateEntry *vmsentry;
QEMUBH *bh;
uint32_t id;
BlockConf conf;
SCSISense unit_attention;
bool sense_is_ua;
uint8_t sense[SCSI_SENSE_BUF_SIZE];
uint32_t sense_len;
QTAILQ_HEAD(, SCSIRequest) requests;
uint32_t channel;
uint32_t lun;
int blocksize;
int type;
uint64_t max_lba;
uint64_t wwn;
uint64_t port_wwn;
int scsi_version;
int default_scsi_version;
bool needs_vpd_bl_emulation;
};
extern const VMStateDescription vmstate_scsi_device;
#define VMSTATE_SCSI_DEVICE(_field, _state) { \
.name = (stringify(_field)), \
.size = sizeof(SCSIDevice), \
.vmsd = &vmstate_scsi_device, \
.flags = VMS_STRUCT, \
.offset = vmstate_offset_value(_state, _field, SCSIDevice), \
}
/* cdrom.c */
int cdrom_read_toc(int nb_sectors, uint8_t *buf, int msf, int start_track);
int cdrom_read_toc_raw(int nb_sectors, uint8_t *buf, int msf, int session_num);
/* scsi-bus.c */
struct SCSIReqOps {
size_t size;
void (*free_req)(SCSIRequest *req);
int32_t (*send_command)(SCSIRequest *req, uint8_t *buf);
void (*read_data)(SCSIRequest *req);
void (*write_data)(SCSIRequest *req);
uint8_t *(*get_buf)(SCSIRequest *req);
void (*save_request)(QEMUFile *f, SCSIRequest *req);
void (*load_request)(QEMUFile *f, SCSIRequest *req);
};
struct SCSIBusInfo {
int tcq;
int max_channel, max_target, max_lun;
int (*parse_cdb)(SCSIDevice *dev, SCSICommand *cmd, uint8_t *buf,
void *hba_private);
void (*transfer_data)(SCSIRequest *req, uint32_t arg);
void (*complete)(SCSIRequest *req, uint32_t arg, size_t resid);
void (*cancel)(SCSIRequest *req);
void (*change)(SCSIBus *bus, SCSIDevice *dev, SCSISense sense);
QEMUSGList *(*get_sg_list)(SCSIRequest *req);
void (*save_request)(QEMUFile *f, SCSIRequest *req);
void *(*load_request)(QEMUFile *f, SCSIRequest *req);
void (*free_request)(SCSIBus *bus, void *priv);
};
#define TYPE_SCSI_BUS "SCSI"
#define SCSI_BUS(obj) OBJECT_CHECK(SCSIBus, (obj), TYPE_SCSI_BUS)
struct SCSIBus {
BusState qbus;
int busnr;
SCSISense unit_attention;
const SCSIBusInfo *info;
};
void scsi_bus_new(SCSIBus *bus, size_t bus_size, DeviceState *host,
const SCSIBusInfo *info, const char *bus_name);
static inline SCSIBus *scsi_bus_from_device(SCSIDevice *d)
{
return DO_UPCAST(SCSIBus, qbus, d->qdev.parent_bus);
}
SCSIDevice *scsi_bus_legacy_add_drive(SCSIBus *bus, BlockBackend *blk,
int unit, bool removable, int bootindex,
bool share_rw,
const char *serial, Error **errp);
void scsi_bus_legacy_handle_cmdline(SCSIBus *bus);
void scsi_legacy_handle_cmdline(void);
SCSIRequest *scsi_req_alloc(const SCSIReqOps *reqops, SCSIDevice *d,
uint32_t tag, uint32_t lun, void *hba_private);
SCSIRequest *scsi_req_new(SCSIDevice *d, uint32_t tag, uint32_t lun,
uint8_t *buf, void *hba_private);
int32_t scsi_req_enqueue(SCSIRequest *req);
SCSIRequest *scsi_req_ref(SCSIRequest *req);
void scsi_req_unref(SCSIRequest *req);
int scsi_bus_parse_cdb(SCSIDevice *dev, SCSICommand *cmd, uint8_t *buf,
void *hba_private);
int scsi_req_parse_cdb(SCSIDevice *dev, SCSICommand *cmd, uint8_t *buf);
void scsi_req_build_sense(SCSIRequest *req, SCSISense sense);
void scsi_req_print(SCSIRequest *req);
void scsi_req_continue(SCSIRequest *req);
void scsi_req_data(SCSIRequest *req, int len);
void scsi_req_complete(SCSIRequest *req, int status);
uint8_t *scsi_req_get_buf(SCSIRequest *req);
int scsi_req_get_sense(SCSIRequest *req, uint8_t *buf, int len);
void scsi_req_cancel_complete(SCSIRequest *req);
void scsi_req_cancel(SCSIRequest *req);
void scsi_req_cancel_async(SCSIRequest *req, Notifier *notifier);
void scsi_req_retry(SCSIRequest *req);
void scsi_device_purge_requests(SCSIDevice *sdev, SCSISense sense);
void scsi_device_set_ua(SCSIDevice *sdev, SCSISense sense);
void scsi_device_report_change(SCSIDevice *dev, SCSISense sense);
void scsi_device_unit_attention_reported(SCSIDevice *dev);
void scsi_generic_read_device_inquiry(SCSIDevice *dev);
int scsi_device_get_sense(SCSIDevice *dev, uint8_t *buf, int len, bool fixed);
int scsi_disk_emulate_vpd_page(SCSIRequest *req, uint8_t *outbuf);
int scsi_SG_IO_FROM_DEV(BlockBackend *blk, uint8_t *cmd, uint8_t cmd_size,
uint8_t *buf, uint8_t buf_size);
SCSIDevice *scsi_device_find(SCSIBus *bus, int channel, int target, int lun);
/* scsi-generic.c. */
extern const SCSIReqOps scsi_generic_req_ops;
#endif