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 <[email protected]> Cc: Christoffer Dall <[email protected]> Cc: Marc Zyngier <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: Will Deacon <[email protected]> Cc: <[email protected]> --- arch/arm64/kvm/hyp/debug-sr.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/arm64/kvm/hyp/debug-sr.c b/arch/arm64/kvm/hyp/debug-sr.c index 321c9c0..f4363d4 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)) -- 1.9.1 _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
