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| author | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-08-31 07:11:45 +0200 |
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| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-08-31 07:11:45 +0200 |
| commit | 5fedf0d295d3ef69fd85fdee4cb68fd3756b54c2 (patch) | |
| tree | 777c39ad4586149de154be3c4c102f751336a37b /arch/x86/entry/calling.h | |
| parent | 3ed8e1c2ac9914a2fcb08ec13476b85319536cea (diff) | |
| parent | f75aef392f869018f78cfedf3c320a6b3fcfda6b (diff) | |
| download | linux-stable-5fedf0d295d3ef69fd85fdee4cb68fd3756b54c2.tar.gz linux-stable-5fedf0d295d3ef69fd85fdee4cb68fd3756b54c2.tar.bz2 linux-stable-5fedf0d295d3ef69fd85fdee4cb68fd3756b54c2.zip | |
Merge 5.9-rc3 into usb-next
We want the USB fixes in here as well.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86/entry/calling.h')
| -rw-r--r-- | arch/x86/entry/calling.h | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/arch/x86/entry/calling.h b/arch/x86/entry/calling.h index 98e4d8886f11..ae9b0d4615b3 100644 --- a/arch/x86/entry/calling.h +++ b/arch/x86/entry/calling.h @@ -374,12 +374,14 @@ For 32-bit we have the following conventions - kernel is built with * Fetch the per-CPU GSBASE value for this processor and put it in @reg. * We normally use %gs for accessing per-CPU data, but we are setting up * %gs here and obviously can not use %gs itself to access per-CPU data. + * + * Do not use RDPID, because KVM loads guest's TSC_AUX on vm-entry and + * may not restore the host's value until the CPU returns to userspace. + * Thus the kernel would consume a guest's TSC_AUX if an NMI arrives + * while running KVM's run loop. */ .macro GET_PERCPU_BASE reg:req - ALTERNATIVE \ - "LOAD_CPU_AND_NODE_SEG_LIMIT \reg", \ - "RDPID \reg", \ - X86_FEATURE_RDPID + LOAD_CPU_AND_NODE_SEG_LIMIT \reg andq $VDSO_CPUNODE_MASK, \reg movq __per_cpu_offset(, \reg, 8), \reg .endm |