Even though ID_AA64MMFR0.PARANGE reports 52 bit PA size support, it cannot be enabled as guest IPA size on 4K or 16K page size configurations. Hence kvm_ipa_limit must be restricted to 48 bits. This change achieves required IPA capping.
Before the commit c9b69a0cf0b4 ("KVM: arm64: Don't constrain maximum IPA size based on host configuration"), the problem here would have been just latent via PHYS_MASK_SHIFT (which earlier in turn capped kvm_ipa_limit), which remains capped at 48 bits on 4K and 16K configs. Cc: Marc Zyngier <m...@kernel.org> Cc: James Morse <james.mo...@arm.com> Cc: Alexandru Elisei <alexandru.eli...@arm.com> Cc: Suzuki K Poulose <suzuki.poul...@arm.com> Cc: Catalin Marinas <catalin.mari...@arm.com> Cc: Will Deacon <w...@kernel.org> Cc: linux-arm-ker...@lists.infradead.org Cc: kvmarm@lists.cs.columbia.edu Cc: linux-ker...@vger.kernel.org Fixes: c9b69a0cf0b4 ("KVM: arm64: Don't constrain maximum IPA size based on host configuration") Signed-off-by: Anshuman Khandual <anshuman.khand...@arm.com> --- This applies on v5.14-rc5 arch/arm64/kvm/reset.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c index 20588220fe66..e66974c4b9d3 100644 --- a/arch/arm64/kvm/reset.c +++ b/arch/arm64/kvm/reset.c @@ -337,6 +337,15 @@ int kvm_set_ipa_limit(void) return -EINVAL; } + /* + * IPA size beyond 48 bits could not be supported + * on either 4K or 16K page size. Hence let's cap + * it to 48 bits, in case it's reported as larger + * on the system. + */ + if (!IS_ENABLED(CONFIG_ARM64_64K_PAGES)) + parange = min(parange, (unsigned int)ID_AA64MMFR0_PARANGE_48); + kvm_ipa_limit = id_aa64mmfr0_parange_to_phys_shift(parange); kvm_info("IPA Size Limit: %d bits%s\n", kvm_ipa_limit, ((kvm_ipa_limit < KVM_PHYS_SHIFT) ? -- 2.20.1 _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm