]> git.ipfire.org Git - thirdparty/kernel/stable.git/commit
arm64/cpufeatures/kvm: Add ARMv8.9 FEAT_ECBHB bits in ID_AA64MMFR1 register
authorNianyao Tang <tangnianyao@huawei.com>
Tue, 11 Jun 2024 12:20:49 +0000 (12:20 +0000)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 28 Aug 2025 14:26:12 +0000 (16:26 +0200)
commit1c0177f0e35fb4b5628d4f9ebec96d8cc1e85892
tree8bc602db817dd1e28cd731015c50b9691a969e97
parent075d3edd725923d31a96891534ddd01cf448fc06
arm64/cpufeatures/kvm: Add ARMv8.9 FEAT_ECBHB bits in ID_AA64MMFR1 register

commit e8cde32f111f7f5681a7bad3ec747e9e697569a9 upstream.

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>
Link: https://lore.kernel.org/r/20240611122049.2758600-1-tangnianyao@huawei.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Patrick Roy <roypat@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arch/arm64/kernel/cpufeature.c