On Tue, Jan 18, 2022 at 4:06 PM Alexander Graf graf@amazon.de wrote:
Hi Matt,
hi Alex,
On 18.01.22 18:46, Matt DeVillier wrote:
and attempting to boot from it:
Booting from Hard Disk... sq 0x7aa77bdf next_sqe 0 sq 0x7aa77bdf commit_sqe 0 cq 0x7aa77bf1 head 0 -> 1 sq 0x7aa77bdf advanced to 1 ns 1 read lba 0+1: 0 Booting from 0000:7c00 sq 0x7aa77bdf next_sqe 1 sq 0x7aa77bdf commit_sqe 1 cq 0x7aa77bf1 head 1 -> 2 sq 0x7aa77bdf advanced to 2 ns 1 read lba 1+1: 0 sq 0x7aa77bdf next_sqe 2 sq 0x7aa77bdf commit_sqe 2 cq 0x7aa77bf1 head 2 -> 3 sq 0x7aa77bdf advanced to 3 read io: 00000000 00000000 00010003 40270002
This error means
"PRP Offset Invalid: The Offset field for a PRP entry is invalid. This may occur when there is a PRP entry with a non-zero offset after the first entry or when the Offset field in any PRP entry is not dword aligned (i.e., bits 1:0 are not cleared to 00b)."
which points towards a misaligned PRP entry. The block size of this request is 105 sectors (52.5kb), so it must be a PRPL. I don't see any obvious code paths that would allow us to ever get into a misaligned request here.
That said, while trying to understand what is happening here I did stumble over a different weird effect: ns->prp1 gets overwritten with 0 by some interrupt handler. Could you please try the patch / hack below and see if it fixes the problem for you? That way I at least know we're hunting the same ghost.
The hack below does indeed work. Not sure if that's good or bad :)
If it doesn't help, I'll send you a debug patch that will give us some more information about the PRP list SeaBIOS assembles.
Thanks,
Alex
diff --git a/src/hw/nvme.c b/src/hw/nvme.c index f035fa2..99ad7a8 100644 --- a/src/hw/nvme.c +++ b/src/hw/nvme.c @@ -257,7 +257,7 @@ nvme_probe_ns(struct nvme_ctrl *ctrl, u32 ns_idx, u8 mdts) goto free_buffer; }
- struct nvme_namespace *ns = malloc_fseg(sizeof(*ns));
- struct nvme_namespace *ns = malloc_low(sizeof(*ns)); if (!ns) { warn_noalloc(); goto free_buffer;
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