[Bug 1875012] Re: UC20 running in OVMF triggers qemu emulation error (cloudimage works fine on the same)

[Juerg Haefliger]

I've setup a UEFI core18 VM and dialed the memory all the way down to
256M but the loop mounting and loading of the kernel still works fine.

Then I've copied grubx64.efi from the core18 image to the core20 image
and now QEMU no longer crashes. So it looks like a change in grub
between 2.02 and 2.04 in combination with UEFI and 'low' memory is
causing this issue.


** Also affects: grub (Ubuntu)
   Importance: Undecided
       Status: New

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Title:
  UC20 running in OVMF triggers qemu emulation error (cloudimage works
  fine on the same)

Status in grub package in Ubuntu:
  New
Status in qemu package in Ubuntu:
  Incomplete
Status in grub source package in Bionic:
  New
Status in qemu source package in Bionic:
  New
Status in grub source package in Eoan:
  New
Status in qemu source package in Eoan:
  New
Status in grub source package in Focal:
  New
Status in qemu source package in Focal:
  New

Bug description:
  Trying to boot a core20 amd64 image on an amd64 Bionic/Eoan/Focal host
  via libvirt leads to:

  KVM internal error. Suberror: 1
  emulation failure
  RAX=0000000000000000 RBX=000000003bdcd5c0 RCX=000000003ff1d030 RDX=00000000000019a0
  RSI=00000000000000ff RDI=000000003bd73ee0 RBP=000000003bd73e40 RSP=000000003ff1d1f8
  R8 =000000003df52168 R9 =0000000000000000 R10=ffffffffffffffff R11=000000003bd44c40
  R12=000000003bd76500 R13=000000003bd73e00 R14=0000000000020002 R15=000000003df4b483
  RIP=00000000000b0000 RFL=00210246 [---Z-P-] CPL=0 II=0 A20=1 SMM=0 HLT=0
  ES =0030 0000000000000000 ffffffff 00c09300 DPL=0 DS   [-WA]
  CS =0038 0000000000000000 ffffffff 00a09b00 DPL=0 CS64 [-RA]
  SS =0030 0000000000000000 ffffffff 00c09300 DPL=0 DS   [-WA]
  DS =0030 0000000000000000 ffffffff 00c09300 DPL=0 DS   [-WA]
  FS =0030 0000000000000000 ffffffff 00c09300 DPL=0 DS   [-WA]
  GS =0030 0000000000000000 ffffffff 00c09300 DPL=0 DS   [-WA]
  LDT=0000 0000000000000000 0000ffff 00008200 DPL=0 LDT
  TR =0000 0000000000000000 0000ffff 00008b00 DPL=0 TSS64-busy
  GDT=     000000003fbee698 00000047
  IDT=     000000003f2d8018 00000fff
  CR0=80010033 CR2=0000000000000000 CR3=000000003fc01000 CR4=00000668
  DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
  DR6=00000000ffff0ff0 DR7=0000000000000400
  EFER=0000000000000d00
  Code=00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <ff> ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff

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