WSL2-Linux-Kernel/arch
Praveen Kumar e5d9b714fe x86/hyperv: fix root partition faults when writing to VP assist page MSR
For root partition the VP assist pages are pre-determined by the
hypervisor. The root kernel is not allowed to change them to
different locations. And thus, we are getting below stack as in
current implementation root is trying to perform write to specific
MSR.

    [ 2.778197] unchecked MSR access error: WRMSR to 0x40000073 (tried to write 0x0000000145ac5001) at rIP: 0xffffffff810c1084 (native_write_msr+0x4/0x30)
    [ 2.784867] Call Trace:
    [ 2.791507] hv_cpu_init+0xf1/0x1c0
    [ 2.798144] ? hyperv_report_panic+0xd0/0xd0
    [ 2.804806] cpuhp_invoke_callback+0x11a/0x440
    [ 2.811465] ? hv_resume+0x90/0x90
    [ 2.818137] cpuhp_issue_call+0x126/0x130
    [ 2.824782] __cpuhp_setup_state_cpuslocked+0x102/0x2b0
    [ 2.831427] ? hyperv_report_panic+0xd0/0xd0
    [ 2.838075] ? hyperv_report_panic+0xd0/0xd0
    [ 2.844723] ? hv_resume+0x90/0x90
    [ 2.851375] __cpuhp_setup_state+0x3d/0x90
    [ 2.858030] hyperv_init+0x14e/0x410
    [ 2.864689] ? enable_IR_x2apic+0x190/0x1a0
    [ 2.871349] apic_intr_mode_init+0x8b/0x100
    [ 2.878017] x86_late_time_init+0x20/0x30
    [ 2.884675] start_kernel+0x459/0x4fb
    [ 2.891329] secondary_startup_64_no_verify+0xb0/0xbb

Since the hypervisor already provides the VP assist pages for root
partition, we need to memremap the memory from hypervisor for root
kernel to use. The mapping is done in hv_cpu_init during bringup and is
unmapped in hv_cpu_die during teardown.

Signed-off-by: Praveen Kumar <kumarpraveen@linux.microsoft.com>
Reviewed-by: Sunil Muthuswamy <sunilmut@microsoft.com>
Link: https://lore.kernel.org/r/20210731120519.17154-1-kumarpraveen@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-08-04 11:56:53 +00:00
..
alpha Kbuild updates for v5.14 2021-07-10 11:01:38 -07:00
arc Kbuild updates for v5.14 2021-07-10 11:01:38 -07:00
arm Kbuild updates for v5.14 2021-07-10 11:01:38 -07:00
arm64 Kbuild updates for v5.14 2021-07-10 11:01:38 -07:00
csky Kbuild updates for v5.14 2021-07-10 11:01:38 -07:00
h8300 Kbuild updates for v5.14 2021-07-10 11:01:38 -07:00
hexagon Kbuild updates for v5.14 2021-07-10 11:01:38 -07:00
ia64 Kbuild updates for v5.14 2021-07-10 11:01:38 -07:00
m68k Kbuild updates for v5.14 2021-07-10 11:01:38 -07:00
microblaze Kbuild updates for v5.14 2021-07-10 11:01:38 -07:00
mips Two fixes: 2021-07-11 11:17:57 -07:00
nds32 Kbuild updates for v5.14 2021-07-10 11:01:38 -07:00
nios2 Kbuild updates for v5.14 2021-07-10 11:01:38 -07:00
openrisc Kbuild updates for v5.14 2021-07-10 11:01:38 -07:00
parisc Kbuild updates for v5.14 2021-07-10 11:01:38 -07:00
powerpc Kbuild updates for v5.14 2021-07-10 11:01:38 -07:00
riscv Kbuild updates for v5.14 2021-07-10 11:01:38 -07:00
s390 Kbuild updates for v5.14 2021-07-10 11:01:38 -07:00
sh Kbuild updates for v5.14 2021-07-10 11:01:38 -07:00
sparc Locking fixes: 2021-07-11 11:06:09 -07:00
um Kbuild updates for v5.14 2021-07-10 11:01:38 -07:00
x86 x86/hyperv: fix root partition faults when writing to VP assist page MSR 2021-08-04 11:56:53 +00:00
xtensa Kbuild updates for v5.14 2021-07-10 11:01:38 -07:00
.gitignore
Kconfig Kconfig: Introduce ARCH_WANTS_NO_INSTR and CC_HAS_NO_PROFILE_FN_ATTR 2021-06-22 11:07:18 -07:00