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Re: conf/files.xen changes proposal

Le 03/07/2013 14:18, rudolf a écrit :
Jean-Yves Migeon wrote:
Le 27/06/13 20:46, rudolf a écrit :
#   compile  XEN3_DOM0_LEN6_9/cpu_ucode_amd.o
/usr/B/tools/bin/x86_64--netbsd-gcc -mcmodel=kernel -mno-red-zone
-ffreestanding -fno-zero-initialized-in-bss -g -O2
-fno-omit-frame-pointer -g -fstack-protector -Wstack-protector --param
ssp-buffer-size=1 -fno-strict-aliasing -std=gnu99 -Werror -Wall
-Wno-main -Wno-format-zero-length -Wpointer-arith -Wmissing-prototypes -Wstrict-prototypes -Wold-style-definition -Wswitch -Wshadow -Wcast-qual -Wwrite-strings -Wno-unreachable-code -Wno-pointer-sign -Wno-attributes -Wextra -Wno-unused-parameter -Wold-style-definition -Wno-sign-compare -march=core2 --sysroot=/usr/B/obj/destdir.amd64 -Damd64 -Dx86_64 -I.
-I/usr/src/sys/../common/include -I/usr/src/sys/arch -I/usr/src/sys
-std=gnu99 -I/usr/src/sys/lib/libkern/../../../common/lib/libc/quad

-I/usr/src/sys/dist/ipf -I/usr/src/sys/external/bsd/acpica/dist/include
-c /usr/src/sys/arch/x86/x86/cpu_ucode_amd.c
cc1: warnings being treated as errors
In file included from /usr/src/sys/arch/x86/x86/cpu_ucode_amd.c:46:0: ./x86/cpu_ucode.h:40:32: error: 'struct cpu_ucode_softc' declared inside
parameter list
./x86/cpu_ucode.h:40:32: error: its scope is only this definition or
declaration, which is probably not what you want

There is definitely something wrong here: cpu_ucode should not pull out
amd cpu_ucode for Xen, but I cannot reproduce that on my host.

I can reproduce the failure with CVS tag netbsd-6-1-RELEASE.

Okay I'll give it a look with your patch.

Removing "dom0ops" from the config flags has side effects.

I don't know the code nor the problematic around the feature, so I
don't see any theoretical reason why the CPU_UCODE feature should be
included in every XEN_DOM0 kernel.

This feature is needed in case you want to upload microcode for a CPU; bug fixing is the main reason. However the hypervisor "sits" between the domain and the hardware, you cannot talk to the CPU directly. Xen implements the "update_microcode" hypercall for that, but your patch probably raises an issue where an #ifdef is likely missing when you comment out the option.

This operation requires privileges (modifying microcode has security consequences), so it is under dom0's responsibility to do it. For evident reasons, domU does not have it.

Jean-Yves Migeon

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