4.14-stable review patch. If anyone has any objections, please let me know.
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From: Julien Thierry julien.thierry@arm.com
commit bfe766cf65fb65e68c4764f76158718560bdcee5 upstream.
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 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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/arm64/kvm/hyp/debug-sr.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/arch/arm64/kvm/hyp/debug-sr.c +++ b/arch/arm64/kvm/hyp/debug-sr.c @@ -84,6 +84,9 @@ static void __hyp_text __debug_save_spe_ { 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))