I would just fix the comment for now, likewise I don't have the time to audit whether the emulation provides full coverage of the standard.
Really there's two cases here 1) We report ATA4-7 (current status), someone discovers missing bits feature Response: They file a ticket on the missing feature. 2) We report ATA3-6 (changed status), legacy stuff checking this bit suddenly break Response: Rabid screeching somewhere in the depths of the internets. Fixing the comment is more risk averse and more likely to produce the desirable outcome (some reads the comment, and discovers a missing ATA feature for the reported standard). -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1908450 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 To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1908450/+subscriptions