Commit 31c00d2aeaa2 ("arm64: Disable fine grained traps on boot") zeroed
the fine grained trap registers to prevent unwanted register traps from
occuring. However, for the PMSNEVFR_EL1 register, the corresponding
HDFG{R,W}TR_EL2.nPMSNEVFR_EL1 fields must be 1 to disable trapping. Set
both fields to 1 if FEAT_SPEv1p2 is detected to disable read and write
traps.
Fixes: 31c00d2aeaa2 ("arm64: Disable fine grained traps on boot")
Signed-off-by: Alexandru Elisei <[email protected]>
---
Based on v5.14-rc7. Tested on the model, using boot-wrapper built from
commit 5cd6238ec4ef ("aarch32: fix .globl replacement"). Without this
patch, in NVHE mode, the model freezes when I try to access PMSNEVFR_EL1.
With this patch, the model doesn't hang anymore.
Changes since v1:
* Set the corresponding bit in HDFGWRTR_EL2 to also disable write traps. My
thanks to Mark for pointing it out.
arch/arm64/include/asm/el2_setup.h | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/include/asm/el2_setup.h
b/arch/arm64/include/asm/el2_setup.h
index b83fb24954b7..3198acb2aad8 100644
--- a/arch/arm64/include/asm/el2_setup.h
+++ b/arch/arm64/include/asm/el2_setup.h
@@ -149,8 +149,17 @@
ubfx x1, x1, #ID_AA64MMFR0_FGT_SHIFT, #4
cbz x1, .Lskip_fgt_\@
- msr_s SYS_HDFGRTR_EL2, xzr
- msr_s SYS_HDFGWTR_EL2, xzr
+ mov x0, xzr
+ mrs x1, id_aa64dfr0_el1
+ ubfx x1, x1, #ID_AA64DFR0_PMSVER_SHIFT, #4
+ cmp x1, #3
+ b.lt .Lset_fgt_\@
+ /* Disable PMSNEVFR_EL1 read and write traps */
+ orr x0, x0, #(1 << 62)
+
+.Lset_fgt_\@:
+ msr_s SYS_HDFGRTR_EL2, x0
+ msr_s SYS_HDFGWTR_EL2, x0
msr_s SYS_HFGRTR_EL2, xzr
msr_s SYS_HFGWTR_EL2, xzr
msr_s SYS_HFGITR_EL2, xzr
--
2.33.0
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