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authorAnshuman Khandual <anshuman.khandual@arm.com>2021-08-11 16:41:15 +0530
committerMarc Zyngier <maz@kernel.org>2021-08-11 16:00:04 +0100
commit5e5df9571c319fb107d7a523cc96fcc99961ee70 (patch)
tree5781052aebcf59f3678d6ca789d8d7c31e11bf87 /arch/arm64/kvm/reset.c
parentb31578f627177bda5c16894e3170a7a6a1236136 (diff)
KVM: arm64: Restrict IPA size to maximum 48 bits on 4K and 16K page size
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.khandual@arm.com
Diffstat (limited to 'arch/arm64/kvm/reset.c')
-rw-r--r--arch/arm64/kvm/reset.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
index 20588220fe66..18ffc6ad67b8 100644
--- a/arch/arm64/kvm/reset.c
+++ b/arch/arm64/kvm/reset.c
@@ -317,6 +317,14 @@ 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