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authorPraveen Kumar <kumarpraveen@linux.microsoft.com>2021-07-31 14:05:19 +0200
committerWei Liu <wei.liu@kernel.org>2021-08-04 13:56:53 +0200
commite5d9b714fe40270222a7de9dcd1cf62dad63eeef (patch)
tree5a75292240f981d4494dd05a092c1a8217e80a9d /arch/x86/include/asm/hyperv-tlfs.h
parenthv: hyperv.h: Remove unused inline functions (diff)
downloadlinux-e5d9b714fe40270222a7de9dcd1cf62dad63eeef.tar.xz
linux-e5d9b714fe40270222a7de9dcd1cf62dad63eeef.zip
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>
Diffstat (limited to 'arch/x86/include/asm/hyperv-tlfs.h')
-rw-r--r--arch/x86/include/asm/hyperv-tlfs.h9
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h
index f1366ce609e3..2322d6bd5883 100644
--- a/arch/x86/include/asm/hyperv-tlfs.h
+++ b/arch/x86/include/asm/hyperv-tlfs.h
@@ -288,6 +288,15 @@ union hv_x64_msr_hypercall_contents {
} __packed;
};
+union hv_vp_assist_msr_contents {
+ u64 as_uint64;
+ struct {
+ u64 enable:1;
+ u64 reserved:11;
+ u64 pfn:52;
+ } __packed;
+};
+
struct hv_reenlightenment_control {
__u64 vector:8;
__u64 reserved1:8;