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| author | Tim Wiederhake <twiederh@redhat.com> | 2026-06-29 19:37:59 +0200 |
|---|---|---|
| committer | Borislav Petkov (AMD) <bp@alien8.de> | 2026-07-20 19:57:33 -0700 |
| commit | b096d79bc1eed9eda57c12ccd76d6797cdba4cf2 (patch) | |
| tree | 3f3677cd2ba9c6cacf7fbcd7128753603a8d80fd | |
| parent | cdb4d57c3e497fe99a9ffa54f085b75130b12b5a (diff) | |
x86/msr: Document the I/O-like write semantics in the msr driver
Explain why msr_write() does not advance the index.
[ bp: Massage commit message. ]
Signed-off-by: Tim Wiederhake <twiederh@redhat.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://patch.msgid.link/20260629173759.1770596-1-twiederh@redhat.com
| -rw-r--r-- | arch/x86/kernel/msr.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/kernel/msr.c b/arch/x86/kernel/msr.c index 34bdb752f892..eb988df22521 100644 --- a/arch/x86/kernel/msr.c +++ b/arch/x86/kernel/msr.c @@ -13,6 +13,9 @@ * and then read/write in chunks of 8 bytes. A larger size means multiple * reads or writes of the same register. * + * Writing the same register multiple times can be useful for MSRs with + * I/O-like semantics, e.g. a virtual MSR that accepts logging information. + * * This driver uses /dev/cpu/%d/msr where %d is the minor number, and on * an SMP box will direct the access to CPU %d. */ |