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Re: [Qemu-devel] [PATCH v3 2/9] hw/block/pflash_cfi01: Use the correct R
From: |
Laszlo Ersek |
Subject: |
Re: [Qemu-devel] [PATCH v3 2/9] hw/block/pflash_cfi01: Use the correct READ_ARRAY value |
Date: |
Fri, 5 Jul 2019 18:46:34 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 |
On 07/05/19 17:46, Philippe Mathieu-Daudé wrote:
> In the "Read Array Flowchart" the command has a value of 0xFF.
>
> In the document [*] the "Read Array Flowchart", the READ_ARRAY
> command has a value of 0xff.
>
> Use the correct value in the pflash model.
>
> There is no change of behavior in the guest, because:
> - when the guest were sending 0xFF, the reset_flash label
> was setting the command value as 0x00
> - 0x00 was used internally for READ_ARRAY
>
> To keep migration behaving correctly, we have to increase
> the VMState version. When migrating from an older version,
> we use the correct command value.
>
> [*] "Common Flash Interface (CFI) and Command Sets"
> (Intel Application Note 646)
> Appendix B "Basic Command Set"
>
> Reviewed-by: John Snow <address@hidden>
> Reviewed-by: Alistair Francis <address@hidden>
> Regression-tested-by: Laszlo Ersek <address@hidden>
> Signed-off-by: Philippe Mathieu-Daudé <address@hidden>
> ---
> v3: Handle migrating the 'cmd' field.
>
> Since Laszlo stated he did not test migration [*], I'm keeping his
> test tag, because the change with v2 has no impact in the tests
> he ran.
My thinking exactly. Thanks!
Laszlo
>
> Likewise I'm keeping John and Alistair tags, but I'd like an extra
> review for the migration change, thanks!
>
> [*] https://lists.gnu.org/archive/html/qemu-devel/2019-07/msg00679.html
> ---
> hw/block/pflash_cfi01.c | 23 +++++++++++++----------
> 1 file changed, 13 insertions(+), 10 deletions(-)
>
> diff --git a/hw/block/pflash_cfi01.c b/hw/block/pflash_cfi01.c
> index 9e34fd4e82..58cbef0588 100644
> --- a/hw/block/pflash_cfi01.c
> +++ b/hw/block/pflash_cfi01.c
> @@ -100,7 +100,7 @@ static int pflash_post_load(void *opaque, int version_id);
>
> static const VMStateDescription vmstate_pflash = {
> .name = "pflash_cfi01",
> - .version_id = 1,
> + .version_id = 2,
> .minimum_version_id = 1,
> .post_load = pflash_post_load,
> .fields = (VMStateField[]) {
> @@ -277,10 +277,9 @@ static uint32_t pflash_read(PFlashCFI01 *pfl, hwaddr
> offset,
> /* This should never happen : reset state & treat it as a read */
> DPRINTF("%s: unknown command state: %x\n", __func__, pfl->cmd);
> pfl->wcycle = 0;
> - pfl->cmd = 0;
> + pfl->cmd = 0xff;
> /* fall through to read code */
> - case 0x00:
> - /* Flash area read */
> + case 0xff: /* Read Array */
> ret = pflash_data_read(pfl, offset, width, be);
> break;
> case 0x10: /* Single byte program */
> @@ -448,8 +447,6 @@ static void pflash_write(PFlashCFI01 *pfl, hwaddr offset,
> case 0:
> /* read mode */
> switch (cmd) {
> - case 0x00: /* ??? */
> - goto reset_flash;
> case 0x10: /* Single Byte Program */
> case 0x40: /* Single Byte Program */
> DPRINTF("%s: Single Byte Program\n", __func__);
> @@ -526,7 +523,7 @@ static void pflash_write(PFlashCFI01 *pfl, hwaddr offset,
> if (cmd == 0xd0) { /* confirm */
> pfl->wcycle = 0;
> pfl->status |= 0x80;
> - } else if (cmd == 0xff) { /* read array mode */
> + } else if (cmd == 0xff) { /* Read Array */
> goto reset_flash;
> } else
> goto error_flash;
> @@ -553,7 +550,7 @@ static void pflash_write(PFlashCFI01 *pfl, hwaddr offset,
> } else if (cmd == 0x01) {
> pfl->wcycle = 0;
> pfl->status |= 0x80;
> - } else if (cmd == 0xff) {
> + } else if (cmd == 0xff) { /* read array mode */
> goto reset_flash;
> } else {
> DPRINTF("%s: Unknown (un)locking command\n", __func__);
> @@ -645,7 +642,7 @@ static void pflash_write(PFlashCFI01 *pfl, hwaddr offset,
> trace_pflash_reset();
> memory_region_rom_device_set_romd(&pfl->mem, true);
> pfl->wcycle = 0;
> - pfl->cmd = 0;
> + pfl->cmd = 0xff;
> }
>
>
> @@ -761,7 +758,7 @@ static void pflash_cfi01_realize(DeviceState *dev, Error
> **errp)
> }
>
> pfl->wcycle = 0;
> - pfl->cmd = 0;
> + pfl->cmd = 0xff;
> pfl->status = 0;
> /* Hardcoded CFI table */
> /* Standard "QRY" string */
> @@ -1001,5 +998,11 @@ static int pflash_post_load(void *opaque, int
> version_id)
> pfl->vmstate = qemu_add_vm_change_state_handler(postload_update_cb,
> pfl);
> }
> + if (version_id < 2) {
> + /* v1 used incorrect value of 0x00 for the READ_ARRAY command. */
> + if (pfl->cmd == 0x00) {
> + pfl->cmd = 0xff;
> + }
> + }
> return 0;
> }
>
[Qemu-devel] [PATCH v3 4/9] hw/block/pflash_cfi01: Start state machine as READY to accept commands, Philippe Mathieu-Daudé, 2019/07/05
[Qemu-devel] [PATCH v3 5/9] hw/block/pflash_cfi01: Add the DeviceReset() handler, Philippe Mathieu-Daudé, 2019/07/05
[Qemu-devel] [PATCH v3 6/9] hw/block/pflash_cfi01: Simplify CFI_QUERY processing, Philippe Mathieu-Daudé, 2019/07/05
[Qemu-devel] [PATCH v3 7/9] hw/block/pflash_cfi01: Improve command comments, Philippe Mathieu-Daudé, 2019/07/05
[Qemu-devel] [PATCH v3 8/9] hw/block/pflash_cfi01: Replace DPRINTF by qemu_log_mask(GUEST_ERROR), Philippe Mathieu-Daudé, 2019/07/05