[Bug 1908450] Re: ide/core.c ATA Major Version reporting incorrect

[Gregory Price]

for what it's worth, i have yet to see a driver actually check this
field.

I have seen a ton of code (OVMF and others) detect other information and
just straight up say "I'm in QEMU" and YOLO a bunch of things like
assuming DMA is available and such, so I somewhat doubt anyone
*actually* checks these fields.

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Title:
  ide/core.c ATA Major Version reporting incorrect

Status in QEMU:
  New

Bug description:
  @@ -165,7 +165,7 @@ static void ide_identify(IDEState *s)
          put_le16(p + 76, (1 << 8));
      }

      put_le16(p + 80, 0xf0); /* ata3 -> ata6 supported */
  -   put_le16(p + 80, 0xf0); /* ata3 -> ata6 supported */
  +   put_le16(p + 80, ((1 << 6) | (1 << 5) (1 << 4) (1 << 3)); /* ata3 -> ata6 
supported */
      put_le16(p + 81, 0x16); /* conforms to ata5 */
      /* 14=NOP supported, 5=WCACHE supported, 0=SMART supported */
      put_le16(p + 82, (1 << 14) | (1 << 5) | 1);

  
  This field Major Version Number field is presently reporting support for 
ATA-4 through ATA-7.
  Bitfield[80] is defined in the ATA-6 specification below.

  0xF0 = (1<<7) | (1<<6) | (1 << 5) | (1 << 4) // 4-7 - current settings
  0x78 = (1<<6) | (1<<5) | (1 << 4) | (1 << 3) // 3-6 - new settings

  Either the comment is wrong, or the field is wrong. If the field is
  wrong it can cause errors in drivers that check support vs conformity.
  This will not break most guests, since the conformity field is set to
  ATA-5.

  I'm not sure whether this component supports ATA-7, but since it's
  commented as if it supports up through 6, correcting the field
  assignment seems more correct.

  ATA/ATAPI-6 Specification
  
https://web.archive.org/web/20200124094822/https://www.t13.org/Documents/UploadedDocuments/project/d1410r3b-ATA-ATAPI-6.pdf

  Page 116
  80 - M Major version number
  0000h or FFFFh = device does not report version
  F 15 Reserved
  F 14 Reserved for ATA/ATAPI-14
  F 13 Reserved for ATA/ATAPI-13
  F 12 Reserved for ATA/ATAPI-12
  F 11 Reserved for ATA/ATAPI-11
  F 10 Reserved for ATA/ATAPI-10
  F 9 Reserved for ATA/ATAPI-9
  F 8 Reserved for ATA/ATAPI-8
  F 7 Reserved for ATA/ATAPI-7
  F 6 1 = supports ATA/ATAPI-6
  F 5 1 = supports ATA/ATAPI-5
  F 4 1 = supports ATA/ATAPI-4
  F 3 1 = supports ATA-3
  X 2 Obsolete
  X 1 Obsolete
  F 0 Reserved

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