From e8cde32f111f7f5681a7bad3ec747e9e697569a9 Mon Sep 17 00:00:00 2001 From: Nianyao Tang Date: Tue, 11 Jun 2024 12:20:49 +0000 Subject: [PATCH] arm64/cpufeatures/kvm: Add ARMv8.9 FEAT_ECBHB bits in ID_AA64MMFR1 register Enable ECBHB bits in ID_AA64MMFR1 register as per ARM DDI 0487K.a specification. When guest OS read ID_AA64MMFR1_EL1, kvm emulate this reg using ftr_id_aa64mmfr1 and always return ID_AA64MMFR1_EL1.ECBHB=0 to guest. It results in guest syscall jump to tramp ventry, which is not needed in implementation with ID_AA64MMFR1_EL1.ECBHB=1. Let's make the guest syscall process the same as the host. Signed-off-by: Nianyao Tang Link: https://lore.kernel.org/r/20240611122049.2758600-1-tangnianyao@huawei.com Signed-off-by: Catalin Marinas --- arch/arm64/kernel/cpufeature.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 48e7029f1054..c3913c90797e 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -429,6 +429,7 @@ static const struct arm64_ftr_bits ftr_id_aa64mmfr0[] = { }; static const struct arm64_ftr_bits ftr_id_aa64mmfr1[] = { + ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_EL1_ECBHB_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_EL1_TIDCP1_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_EL1_AFP_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_EL1_HCX_SHIFT, 4, 0), -- 2.50.1