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Re: [Qemu-devel] [PATCH v3] Add "cache" parameter to "-drive"
From: |
andrzej zaborowski |
Subject: |
Re: [Qemu-devel] [PATCH v3] Add "cache" parameter to "-drive" |
Date: |
Mon, 24 Dec 2007 15:34:44 +0100 |
Hi,
On 18/12/2007, Laurent Vivier <address@hidden> wrote:
> This patch adds a new parameter to "-drive"
>
> Using "cache=off" with "-drive" will open the disk image file using
> "O_DIRECT".
>
> By default, "cache" is set to "on" to keep original behavior of qemu.
>
> v3 modify hw/sd.c to allocate buffer on init and not on each
> blk_read()/blk_write()
> and add "cache=" in qemu-doc.texi.
>
>
> example:
>
> "-drive file=my_disk.qcow2,cache=off"
> ---
> block-raw-posix.c | 8 +++++++
> block-raw-win32.c | 4 +++
> block.c | 2 -
> block.h | 1
> hw/fdc.c | 7 +++++-
> hw/ide.c | 18 +++++++++++++----
> hw/scsi-disk.c | 3 +-
> hw/sd.c | 56
> ++++++++++++++++++++++++++----------------------------
> osdep.c | 20 +++++++++++++++++++
> osdep.h | 1
> qemu-doc.texi | 2 +
> vl.c | 28 +++++++++++++++++++++++----
> 12 files changed, 110 insertions(+), 40 deletions(-)
>
> Index: qemu/block.c
> ===================================================================
> --- qemu.orig/block.c 2007-12-18 10:58:14.000000000 +0100
> +++ qemu/block.c 2007-12-18 11:01:01.000000000 +0100
> @@ -380,7 +380,7 @@ int bdrv_open2(BlockDriverState *bs, con
> /* Note: for compatibility, we open disk image files as RDWR, and
> RDONLY as fallback */
> if (!(flags & BDRV_O_FILE))
> - open_flags = BDRV_O_RDWR;
> + open_flags = BDRV_O_RDWR | (flags & BDRV_O_DIRECT);
> else
> open_flags = flags & ~(BDRV_O_FILE | BDRV_O_SNAPSHOT);
> ret = drv->bdrv_open(bs, filename, open_flags);
> Index: qemu/block.h
> ===================================================================
> --- qemu.orig/block.h 2007-12-18 10:58:14.000000000 +0100
> +++ qemu/block.h 2007-12-18 11:01:01.000000000 +0100
> @@ -44,6 +44,7 @@ typedef struct QEMUSnapshotInfo {
> use a disk image format on top of
> it (default for
> bdrv_file_open()) */
> +#define BDRV_O_DIRECT 0x0020
>
> #ifndef QEMU_IMG
> void bdrv_info(void);
> Index: qemu/hw/fdc.c
> ===================================================================
> --- qemu.orig/hw/fdc.c 2007-12-18 10:58:14.000000000 +0100
> +++ qemu/hw/fdc.c 2007-12-18 11:01:01.000000000 +0100
> @@ -382,7 +382,7 @@ struct fdctrl_t {
> uint8_t cur_drv;
> uint8_t bootsel;
> /* Command FIFO */
> - uint8_t fifo[FD_SECTOR_LEN];
> + uint8_t *fifo;
> uint32_t data_pos;
> uint32_t data_len;
> uint8_t data_state;
> @@ -598,6 +598,11 @@ fdctrl_t *fdctrl_init (qemu_irq irq, int
> fdctrl = qemu_mallocz(sizeof(fdctrl_t));
> if (!fdctrl)
> return NULL;
> + fdctrl->fifo = qemu_memalign(512, FD_SECTOR_LEN);
> + if (fdctrl->fifo == NULL) {
> + qemu_free(fdctrl);
> + return NULL;
> + }
> fdctrl->result_timer = qemu_new_timer(vm_clock,
> fdctrl_result_timer, fdctrl);
>
> Index: qemu/hw/ide.c
> ===================================================================
> --- qemu.orig/hw/ide.c 2007-12-18 10:58:14.000000000 +0100
> +++ qemu/hw/ide.c 2007-12-18 11:01:01.000000000 +0100
> @@ -365,7 +365,7 @@ typedef struct IDEState {
> EndTransferFunc *end_transfer_func;
> uint8_t *data_ptr;
> uint8_t *data_end;
> - uint8_t io_buffer[MAX_MULT_SECTORS*512 + 4];
> + uint8_t *io_buffer;
> QEMUTimer *sector_write_timer; /* only used for win2k install hack */
> uint32_t irq_count; /* counts IRQs when using win2k install hack */
> /* CF-ATA extended error */
> @@ -2377,17 +2377,24 @@ struct partition {
> static int guess_disk_lchs(IDEState *s,
> int *pcylinders, int *pheads, int *psectors)
> {
> - uint8_t buf[512];
> + uint8_t *buf;
> int ret, i, heads, sectors, cylinders;
> struct partition *p;
> uint32_t nr_sects;
>
> + buf = qemu_memalign(512, 512);
> + if (buf == NULL)
> + return -1;
> ret = bdrv_read(s->bs, 0, buf, 1);
> - if (ret < 0)
> + if (ret < 0) {
> + qemu_free(buf);
> return -1;
> + }
> /* test msdos magic */
> - if (buf[510] != 0x55 || buf[511] != 0xaa)
> + if (buf[510] != 0x55 || buf[511] != 0xaa) {
> + qemu_free(buf);
> return -1;
> + }
> for(i = 0; i < 4; i++) {
> p = ((struct partition *)(buf + 0x1be)) + i;
> nr_sects = le32_to_cpu(p->nr_sects);
> @@ -2408,9 +2415,11 @@ static int guess_disk_lchs(IDEState *s,
> printf("guessed geometry: LCHS=%d %d %d\n",
> cylinders, heads, sectors);
> #endif
> + qemu_free(buf);
> return 0;
> }
> }
> + qemu_free(buf);
> return -1;
> }
>
> @@ -2425,6 +2434,7 @@ static void ide_init2(IDEState *ide_stat
>
> for(i = 0; i < 2; i++) {
> s = ide_state + i;
> + s->io_buffer = qemu_memalign(512, MAX_MULT_SECTORS*512 + 4);
> if (i == 0)
> s->bs = hd0;
> else
> Index: qemu/hw/scsi-disk.c
> ===================================================================
> --- qemu.orig/hw/scsi-disk.c 2007-12-18 10:58:14.000000000 +0100
> +++ qemu/hw/scsi-disk.c 2007-12-18 11:01:01.000000000 +0100
> @@ -46,7 +46,7 @@ typedef struct SCSIRequest {
> int sector_count;
> /* The amounnt of data in the buffer. */
> int buf_len;
> - uint8_t dma_buf[SCSI_DMA_BUF_SIZE];
> + uint8_t *dma_buf;
> BlockDriverAIOCB *aiocb;
> struct SCSIRequest *next;
> } SCSIRequest;
> @@ -78,6 +78,7 @@ static SCSIRequest *scsi_new_request(SCS
> free_requests = r->next;
> } else {
> r = qemu_malloc(sizeof(SCSIRequest));
> + r->dma_buf = qemu_memalign(512, SCSI_DMA_BUF_SIZE);
> }
> r->dev = s;
> r->tag = tag;
> Index: qemu/hw/sd.c
> ===================================================================
> --- qemu.orig/hw/sd.c 2007-12-18 10:58:14.000000000 +0100
> +++ qemu/hw/sd.c 2007-12-18 11:19:19.000000000 +0100
> @@ -96,6 +96,7 @@ struct SDState {
> qemu_irq readonly_cb;
> qemu_irq inserted_cb;
> BlockDriverState *bdrv;
> + uint8_t *buf;
> };
>
> static void sd_set_status(SDState *sd)
> @@ -405,6 +406,7 @@ SDState *sd_init(BlockDriverState *bs, i
> SDState *sd;
>
> sd = (SDState *) qemu_mallocz(sizeof(SDState));
> + sd->buf = qemu_memalign(512, 512);
> sd->spi = is_spi;
> sd_reset(sd, bs);
> bdrv_set_change_cb(sd->bdrv, sd_cardchange, sd);
> @@ -1281,64 +1283,60 @@ int sd_do_command(SDState *sd, struct sd
> }
>
> /* No real need for 64 bit addresses here */
> -static void sd_blk_read(BlockDriverState *bdrv,
> - void *data, uint32_t addr, uint32_t len)
> +static void sd_blk_read(SDState *sd)
> {
> - uint8_t buf[512];
> - uint32_t end = addr + len;
> + uint32_t addr = sd->data_start;
> + uint32_t end = addr + sd->blk_len;
>
> - if (!bdrv || bdrv_read(bdrv, addr >> 9, buf, 1) == -1) {
> + if (!sd->bdrv || bdrv_read(sd->bdrv, addr >> 9, sd->buf, 1) == -1) {
> printf("sd_blk_read: read error on host side\n");
> return;
> }
>
> if (end > (addr & ~511) + 512) {
> - memcpy(data, buf + (addr & 511), 512 - (addr & 511));
> + memcpy(sd->data, sd->buf + (addr & 511), 512 - (addr & 511));
>
> - if (bdrv_read(bdrv, end >> 9, buf, 1) == -1) {
> + if (bdrv_read(sd->bdrv, end >> 9, sd->buf, 1) == -1) {
> printf("sd_blk_read: read error on host side\n");
> return;
> }
> - memcpy(data + 512 - (addr & 511), buf, end & 511);
> + memcpy(sd->data + 512 - (addr & 511), sd->buf, end & 511);
> } else
> - memcpy(data, buf + (addr & 511), len);
> + memcpy(sd->data, sd->buf + (addr & 511), sd->blk_len);
> }
>
> -static void sd_blk_write(BlockDriverState *bdrv,
> - void *data, uint32_t addr, uint32_t len)
> +static void sd_blk_write(SDState *sd)
> {
> - uint8_t buf[512];
> - uint32_t end = addr + len;
> + uint32_t addr = sd->data_start;
> + uint32_t end = addr + sd->blk_len;
>
> - if ((addr & 511) || len < 512)
> - if (!bdrv || bdrv_read(bdrv, addr >> 9, buf, 1) == -1) {
> + if ((addr & 511) || sd->blk_len < 512)
> + if (!sd->bdrv || bdrv_read(sd->bdrv, addr >> 9, sd->buf, 1) == -1) {
> printf("sd_blk_write: read error on host side\n");
> return;
> }
>
> if (end > (addr & ~511) + 512) {
> - memcpy(buf + (addr & 511), data, 512 - (addr & 511));
> - if (bdrv_write(bdrv, addr >> 9, buf, 1) == -1) {
> + memcpy(sd->buf + (addr & 511), sd->data, 512 - (addr & 511));
> + if (bdrv_write(sd->bdrv, addr >> 9, sd->buf, 1) == -1) {
> printf("sd_blk_write: write error on host side\n");
> return;
> }
>
> - if (bdrv_read(bdrv, end >> 9, buf, 1) == -1) {
> + if (bdrv_read(sd->bdrv, end >> 9, sd->buf, 1) == -1) {
> printf("sd_blk_write: read error on host side\n");
> return;
> }
> - memcpy(buf, data + 512 - (addr & 511), end & 511);
> - if (bdrv_write(bdrv, end >> 9, buf, 1) == -1)
> + memcpy(sd->buf, sd->data + 512 - (addr & 511), end & 511);
> + if (bdrv_write(sd->bdrv, end >> 9, sd->buf, 1) == -1)
> printf("sd_blk_write: write error on host side\n");
> } else {
> - memcpy(buf + (addr & 511), data, len);
> - if (!bdrv || bdrv_write(bdrv, addr >> 9, buf, 1) == -1)
> + memcpy(sd->buf + (addr & 511), sd->data, sd->blk_len);
> + if (!sd->bdrv || bdrv_write(sd->bdrv, addr >> 9, sd->buf, 1) == -1)
> printf("sd_blk_write: write error on host side\n");
> }
> }
>
> -#define BLK_READ_BLOCK(a, len) sd_blk_read(sd->bdrv, sd->data, a, len)
> -#define BLK_WRITE_BLOCK(a, len) sd_blk_write(sd->bdrv, sd->data, a,
> len)
I committed the patch but I retained the use of these macros in sd.c
because they make sense to me.
Thanks,
Andrew