Currently the RAS feature bit is not writable in ID_AA64PFR0EL1, this makes migration fail when migration from the machine which RAS is 1 to another machine which RAS is 2.
Allow RAS writable from userspace would make the migration possible between two machines which RAS is different.
Shaoqin Huang (2): KVM: arm64: Use kvm_has_feat() to check if FEAT_RAS is advertised to the guest KVM: arm64: Allow the RAS feature bit in ID_AA64PFR0_EL1 writable from userspace
arch/arm64/kvm/guest.c | 4 ++-- arch/arm64/kvm/handle_exit.c | 2 +- arch/arm64/kvm/hyp/include/hyp/switch.h | 2 +- arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h | 7 +++++-- arch/arm64/kvm/sys_regs.c | 3 +-- tools/testing/selftests/kvm/aarch64/set_id_regs.c | 1 + 6 files changed, 11 insertions(+), 8 deletions(-)
Currently FEAT_RAS is not writable, this makes migration fail between systems where this feature differ. Allow the FEAT_RAS writable in ID_AA64PFR0_EL1 to let the migration possible when the RAS is differ between two machines.
Also update the kselftest to test the RAS field.
Signed-off-by: Shaoqin Huang shahuang@redhat.com --- arch/arm64/kvm/sys_regs.c | 1 - tools/testing/selftests/kvm/aarch64/set_id_regs.c | 1 + 2 files changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index b09f8ba3525b..51ff66a11793 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -2364,7 +2364,6 @@ static const struct sys_reg_desc sys_reg_descs[] = { .val = ~(ID_AA64PFR0_EL1_AMU | ID_AA64PFR0_EL1_MPAM | ID_AA64PFR0_EL1_SVE | - ID_AA64PFR0_EL1_RAS | ID_AA64PFR0_EL1_GIC | ID_AA64PFR0_EL1_AdvSIMD | ID_AA64PFR0_EL1_FP), }, diff --git a/tools/testing/selftests/kvm/aarch64/set_id_regs.c b/tools/testing/selftests/kvm/aarch64/set_id_regs.c index d20981663831..d2dd78ce0e02 100644 --- a/tools/testing/selftests/kvm/aarch64/set_id_regs.c +++ b/tools/testing/selftests/kvm/aarch64/set_id_regs.c @@ -126,6 +126,7 @@ static const struct reg_ftr_bits ftr_id_aa64pfr0_el1[] = { REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64PFR0_EL1, CSV2, 0), REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64PFR0_EL1, DIT, 0), REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64PFR0_EL1, SEL2, 0), + REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64PFR0_EL1, RAS, 0), REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64PFR0_EL1, EL3, 0), REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64PFR0_EL1, EL2, 0), REG_FTR_BITS(FTR_LOWER_SAFE, ID_AA64PFR0_EL1, EL1, 0),
On Wed, Sep 25, 2024 at 11:22:40PM -0400, Shaoqin Huang wrote:
Currently FEAT_RAS is not writable, this makes migration fail between systems where this feature differ. Allow the FEAT_RAS writable in ID_AA64PFR0_EL1 to let the migration possible when the RAS is differ between two machines.
Also update the kselftest to test the RAS field.
Please do kernel + selftests changes in separate patches.
linux-kselftest-mirror@lists.linaro.org