| Message ID | 20240611122049.2758600-1-tangnianyao@huawei.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | arm64/cpufeatures/kvm: Add ARMv8.9 FEAT_ECBHB bits in ID_AA64MMFR1 register | expand |
On Tue, 11 Jun 2024 12:20:49 +0000, Nianyao Tang wrote: > 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. > > [...] Applied to arm64 (for-next/cpufeature), thanks! [1/1] arm64/cpufeatures/kvm: Add ARMv8.9 FEAT_ECBHB bits in ID_AA64MMFR1 register https://git.kernel.org/arm64/c/e8cde32f111f
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),
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 <tangnianyao@huawei.com> --- arch/arm64/kernel/cpufeature.c | 1 + 1 file changed, 1 insertion(+)