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| author | Oliver Upton <oliver.upton@linux.dev> | 2023-10-04 01:04:02 +0200 |
|---|---|---|
| committer | Oliver Upton <oliver.upton@linux.dev> | 2023-10-04 19:11:50 +0200 |
| commit | 56d77aa8bdf527f3b767fa27a3f135769151c92d (patch) | |
| tree | 9578b9864a2171fda390fa21d222c2ae1a1da9c5 /arch/arm64 | |
| parent | KVM: arm64: Bump up the default KVM sanitised debug version to v8p8 (diff) | |
| download | linux-56d77aa8bdf527f3b767fa27a3f135769151c92d.tar.xz linux-56d77aa8bdf527f3b767fa27a3f135769151c92d.zip | |
KVM: arm64: Allow userspace to change ID_AA64ISAR{0-2}_EL1
Almost all of the features described by the ISA registers have no KVM
involvement. Allow userspace to change the value of these registers with
a couple exceptions:
- MOPS is not writable as KVM does not currently virtualize FEAT_MOPS.
- The PAuth fields are not writable as KVM requires both address and
generic authentication be enabled.
Co-developed-by: Jing Zhang <jingzhangos@google.com>
Signed-off-by: Jing Zhang <jingzhangos@google.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20231003230408.3405722-7-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Diffstat (limited to 'arch/arm64')
| -rw-r--r-- | arch/arm64/kvm/sys_regs.c | 38 |
1 files changed, 26 insertions, 12 deletions
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index c28d864a6807..5d1a94af42f2 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -1851,11 +1851,14 @@ static unsigned int elx2_visibility(const struct kvm_vcpu *vcpu, * from userspace. */ -/* sys_reg_desc initialiser for known cpufeature ID registers */ -#define ID_SANITISED(name) { \ +#define ID_DESC(name) \ SYS_DESC(SYS_##name), \ .access = access_id_reg, \ - .get_user = get_id_reg, \ + .get_user = get_id_reg \ + +/* sys_reg_desc initialiser for known cpufeature ID registers */ +#define ID_SANITISED(name) { \ + ID_DESC(name), \ .set_user = set_id_reg, \ .visibility = id_visibility, \ .reset = kvm_read_sanitised_id_reg, \ @@ -1864,15 +1867,22 @@ static unsigned int elx2_visibility(const struct kvm_vcpu *vcpu, /* sys_reg_desc initialiser for known cpufeature ID registers */ #define AA32_ID_SANITISED(name) { \ - SYS_DESC(SYS_##name), \ - .access = access_id_reg, \ - .get_user = get_id_reg, \ + ID_DESC(name), \ .set_user = set_id_reg, \ .visibility = aa32_id_visibility, \ .reset = kvm_read_sanitised_id_reg, \ .val = 0, \ } +/* sys_reg_desc initialiser for writable ID registers */ +#define ID_WRITABLE(name, mask) { \ + ID_DESC(name), \ + .set_user = set_id_reg, \ + .visibility = id_visibility, \ + .reset = kvm_read_sanitised_id_reg, \ + .val = mask, \ +} + /* * sys_reg_desc initialiser for architecturally unallocated cpufeature ID * register with encoding Op0=3, Op1=0, CRn=0, CRm=crm, Op2=op2 @@ -1894,9 +1904,7 @@ static unsigned int elx2_visibility(const struct kvm_vcpu *vcpu, * RAZ for the guest. */ #define ID_HIDDEN(name) { \ - SYS_DESC(SYS_##name), \ - .access = access_id_reg, \ - .get_user = get_id_reg, \ + ID_DESC(name), \ .set_user = set_id_reg, \ .visibility = raz_visibility, \ .reset = kvm_read_sanitised_id_reg, \ @@ -2075,9 +2083,15 @@ static const struct sys_reg_desc sys_reg_descs[] = { ID_UNALLOCATED(5,7), /* CRm=6 */ - ID_SANITISED(ID_AA64ISAR0_EL1), - ID_SANITISED(ID_AA64ISAR1_EL1), - ID_SANITISED(ID_AA64ISAR2_EL1), + ID_WRITABLE(ID_AA64ISAR0_EL1, ~ID_AA64ISAR0_EL1_RES0), + ID_WRITABLE(ID_AA64ISAR1_EL1, ~(ID_AA64ISAR1_EL1_GPI | + ID_AA64ISAR1_EL1_GPA | + ID_AA64ISAR1_EL1_API | + ID_AA64ISAR1_EL1_APA)), + ID_WRITABLE(ID_AA64ISAR2_EL1, ~(ID_AA64ISAR2_EL1_RES0 | + ID_AA64ISAR2_EL1_MOPS | + ID_AA64ISAR2_EL1_APA3 | + ID_AA64ISAR2_EL1_GPA3)), ID_UNALLOCATED(6,3), ID_UNALLOCATED(6,4), ID_UNALLOCATED(6,5), |