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| author | Julien Thierry <julien.thierry@arm.com> | 2017-12-06 18:09:49 +0100 |
|---|---|---|
| committer | Christoffer Dall <christoffer.dall@linaro.org> | 2017-12-18 10:53:22 +0100 |
| commit | bfe766cf65fb65e68c4764f76158718560bdcee5 (patch) | |
| tree | dbca7a94f09182a850f02f0d521c87b470eedfd8 | |
| parent | Linux 4.15-rc3 (diff) | |
| download | linux-bfe766cf65fb65e68c4764f76158718560bdcee5.tar.xz linux-bfe766cf65fb65e68c4764f76158718560bdcee5.zip | |
arm64: kvm: Prevent restoring stale PMSCR_EL1 for vcpu
When VHE is not present, KVM needs to save and restores PMSCR_EL1 when
possible. If SPE is used by the host, value of PMSCR_EL1 cannot be saved
for the guest.
If the host starts using SPE between two save+restore on the same vcpu,
restore will write the value of PMSCR_EL1 read during the first save.
Make sure __debug_save_spe_nvhe clears the value of the saved PMSCR_EL1
when the guest cannot use SPE.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Cc: Christoffer Dall <christoffer.dall@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: <stable@vger.kernel.org>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
| -rw-r--r-- | arch/arm64/kvm/hyp/debug-sr.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp/debug-sr.c b/arch/arm64/kvm/hyp/debug-sr.c index 321c9c05dd9e..f4363d40e2cd 100644 --- a/arch/arm64/kvm/hyp/debug-sr.c +++ b/arch/arm64/kvm/hyp/debug-sr.c @@ -74,6 +74,9 @@ static void __hyp_text __debug_save_spe_nvhe(u64 *pmscr_el1) { u64 reg; + /* Clear pmscr in case of early return */ + *pmscr_el1 = 0; + /* SPE present on this CPU? */ if (!cpuid_feature_extract_unsigned_field(read_sysreg(id_aa64dfr0_el1), ID_AA64DFR0_PMSVER_SHIFT)) |