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| author | Oliver Upton <oliver.upton@linux.dev> | 2023-06-09 22:00:47 +0300 |
|---|---|---|
| committer | Oliver Upton <oliver.upton@linux.dev> | 2023-06-13 02:08:33 +0300 |
| commit | f90f9360c3d7fbb731732fbb9a1228f55d178e10 (patch) | |
| tree | ac03304049c6359316a9e1549a9e20ebdc8a9373 /arch/arm64/include/asm/kvm_host.h | |
| parent | 2251e9ff1573a266102f40e507f0b8dc5861f3e4 (diff) | |
| download | linux-f90f9360c3d7fbb731732fbb9a1228f55d178e10.tar.xz | |
KVM: arm64: Rewrite IMPDEF PMU version as NI
KVM allows userspace to write an IMPDEF PMU version to the corresponding
32bit and 64bit ID register fields for the sake of backwards
compatibility with kernels that lacked commit 3d0dba5764b9 ("KVM: arm64:
PMU: Move the ID_AA64DFR0_EL1.PMUver limit to VM creation"). Plumbing
that IMPDEF PMU version through to the gues is getting in the way of
progress, and really doesn't any sense in the first place.
Bite the bullet and reinterpret the IMPDEF PMU version as NI (0) for
userspace writes. Additionally, spill the dirty details into a comment.
Link: https://lore.kernel.org/r/20230609190054.1542113-5-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Diffstat (limited to 'arch/arm64/include/asm/kvm_host.h')
| -rw-r--r-- | arch/arm64/include/asm/kvm_host.h | 5 |
1 files changed, 1 insertions, 4 deletions
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 2c8c4ace81ef..44da989435fc 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -241,10 +241,7 @@ struct kvm_arch { u8 pfr0_csv2; u8 pfr0_csv3; - struct { - u8 imp:4; - u8 unimp:4; - } dfr0_pmuver; + u8 dfr0_pmuver; /* Hypercall features firmware registers' descriptor */ struct kvm_smccc_features smccc_feat; |