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Commit 8a74c8e8 authored by Julien Thierry's avatar Julien Thierry Committed by Greg Kroah-Hartman
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arm64: kvm: Prevent restoring stale PMSCR_EL1 for vcpu 



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: default avatarJulien 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: default avatarWill Deacon <will.deacon@arm.com>
Reviewed-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent efc9b7ae

arch/arm64/kvm/hyp/debug-sr.c

+3 −0
Original line number Diff line number Diff line
@@ -84,6 +84,9 @@ 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))