diff options
Diffstat (limited to 'Documentation/arch')
| -rw-r--r-- | Documentation/arch/arm64/booting.rst | 22 | ||||
| -rw-r--r-- | Documentation/arch/x86/mds.rst | 8 |
2 files changed, 26 insertions, 4 deletions
diff --git a/Documentation/arch/arm64/booting.rst b/Documentation/arch/arm64/booting.rst index b57776a68f15..15bcd1b4003a 100644 --- a/Documentation/arch/arm64/booting.rst +++ b/Documentation/arch/arm64/booting.rst @@ -285,6 +285,12 @@ Before jumping into the kernel, the following conditions must be met: - SCR_EL3.FGTEn (bit 27) must be initialised to 0b1. + For CPUs with the Fine Grained Traps 2 (FEAT_FGT2) extension present: + + - If EL3 is present and the kernel is entered at EL2: + + - SCR_EL3.FGTEn2 (bit 59) must be initialised to 0b1. + For CPUs with support for HCRX_EL2 (FEAT_HCX) present: - If EL3 is present and the kernel is entered at EL2: @@ -379,6 +385,22 @@ Before jumping into the kernel, the following conditions must be met: - SMCR_EL2.EZT0 (bit 30) must be initialised to 0b1. + For CPUs with the Performance Monitors Extension (FEAT_PMUv3p9): + + - If EL3 is present: + + - MDCR_EL3.EnPM2 (bit 7) must be initialised to 0b1. + + - If the kernel is entered at EL1 and EL2 is present: + + - HDFGRTR2_EL2.nPMICNTR_EL0 (bit 2) must be initialised to 0b1. + - HDFGRTR2_EL2.nPMICFILTR_EL0 (bit 3) must be initialised to 0b1. + - HDFGRTR2_EL2.nPMUACR_EL1 (bit 4) must be initialised to 0b1. + + - HDFGWTR2_EL2.nPMICNTR_EL0 (bit 2) must be initialised to 0b1. + - HDFGWTR2_EL2.nPMICFILTR_EL0 (bit 3) must be initialised to 0b1. + - HDFGWTR2_EL2.nPMUACR_EL1 (bit 4) must be initialised to 0b1. + For CPUs with Memory Copy and Memory Set instructions (FEAT_MOPS): - If the kernel is entered at EL1 and EL2 is present: diff --git a/Documentation/arch/x86/mds.rst b/Documentation/arch/x86/mds.rst index 5a2e6c0ef04a..3518671e1a85 100644 --- a/Documentation/arch/x86/mds.rst +++ b/Documentation/arch/x86/mds.rst @@ -93,7 +93,7 @@ enters a C-state. The kernel provides a function to invoke the buffer clearing: - mds_clear_cpu_buffers() + x86_clear_cpu_buffers() Also macro CLEAR_CPU_BUFFERS can be used in ASM late in exit-to-user path. Other than CFLAGS.ZF, this macro doesn't clobber any registers. @@ -185,9 +185,9 @@ Mitigation points idle clearing would be a window dressing exercise and is therefore not activated. - The invocation is controlled by the static key mds_idle_clear which is - switched depending on the chosen mitigation mode and the SMT state of - the system. + The invocation is controlled by the static key cpu_buf_idle_clear which is + switched depending on the chosen mitigation mode and the SMT state of the + system. The buffer clear is only invoked before entering the C-State to prevent that stale data from the idling CPU from spilling to the Hyper-Thread |