4b9637cd89
[ Upstream commit 0471a7bd1bca2a47a5f378f2222c5cf39ce94152 ] Certain guest operating systems (e.g., UNIXWARE) clear bit 0 of MC1_CTL to ignore single-bit ECC data errors. Single-bit ECC data errors are always correctable and thus are safe to ignore because they are informational in nature rather than signaling a loss of data integrity. Prior to this patch, these guests would crash upon writing MC1_CTL, with resultant error messages like the following: error: kvm run failed Operation not permitted EAX=fffffffe EBX=fffffffe ECX=00000404 EDX=ffffffff ESI=ffffffff EDI=00000001 EBP=fffdaba4 ESP=fffdab20 EIP=c01333a5 EFL=00000246 [---Z-P-] CPL=0 II=0 A20=1 SMM=0 HLT=0 ES =0108 00000000 ffffffff 00c09300 DPL=0 DS [-WA] CS =0100 00000000 ffffffff 00c09b00 DPL=0 CS32 [-RA] SS =0108 00000000 ffffffff 00c09300 DPL=0 DS [-WA] DS =0108 00000000 ffffffff 00c09300 DPL=0 DS [-WA] FS =0000 00000000 ffffffff 00c00000 GS =0000 00000000 ffffffff 00c00000 LDT=0118 c1026390 00000047 00008200 DPL=0 LDT TR =0110 ffff5af0 00000067 00008b00 DPL=0 TSS32-busy GDT= ffff5020 000002cf IDT= ffff52f0 000007ff CR0=8001003b CR2=00000000 CR3=0100a000 CR4=00000230 DR0=00000000 DR1=00000000 DR2=00000000 DR3=00000000 DR6=ffff0ff0 DR7=00000400 EFER=0000000000000000 Code=08 89 01 89 51 04 c3 8b 4c 24 08 8b 01 8b 51 04 8b 4c 24 04 <0f> 30 c3 f7 05 a4 6d ff ff 10 00 00 00 74 03 0f 31 c3 33 c0 33 d2 c3 8d 74 26 00 0f 31 c3 Signed-off-by: Lev Kujawski <lkujaw@member.fsf.org> Message-Id: <20220521081511.187388-1-lkujaw@member.fsf.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.