From: Anshuman Khandual anshuman.khandual@arm.com
[ Upstream commit 5e5df9571c319fb107d7a523cc96fcc99961ee70 ]
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 maz@kernel.org Cc: James Morse james.morse@arm.com Cc: Alexandru Elisei alexandru.elisei@arm.com Cc: Suzuki K Poulose suzuki.poulose@arm.com Cc: Catalin Marinas catalin.marinas@arm.com Cc: Will Deacon will@kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: kvmarm@lists.cs.columbia.edu Cc: linux-kernel@vger.kernel.org Fixes: c9b69a0cf0b4 ("KVM: arm64: Don't constrain maximum IPA size based on host configuration") Signed-off-by: Anshuman Khandual anshuman.khandual@arm.com Signed-off-by: Marc Zyngier maz@kernel.org Link: https://lore.kernel.org/r/1628680275-16578-1-git-send-email-anshuman.khandua... Signed-off-by: Sasha Levin sashal@kernel.org --- arch/arm64/kvm/reset.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c index b969c2157ad2..6058a80ec9ec 100644 --- a/arch/arm64/kvm/reset.c +++ b/arch/arm64/kvm/reset.c @@ -366,6 +366,14 @@ int kvm_set_ipa_limit(void) mmfr0 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1); parange = cpuid_feature_extract_unsigned_field(mmfr0, ID_AA64MMFR0_PARANGE_SHIFT); + /* + * 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 (PAGE_SIZE != SZ_64K) + parange = min(parange, (unsigned int)ID_AA64MMFR0_PARANGE_48);
/* * Check with ARMv8.5-GTG that our PAGE_SIZE is supported at