From ff2e23a6c1b356db251d47ce1837ac6b713050b8 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Thu, 12 Dec 2024 09:18:45 +0100 Subject: [PATCH] arm64/kvm: Configure HYP TCR.PS/DS based on host stage1 BugLink: https://bugs.launchpad.net/bugs/2114239 commit f0da16992aef7e246b2f3bba1492e3a52c38ca0e upstream. When the host stage1 is configured for LPA2, the value currently being programmed into TCR_EL2.T0SZ may be invalid unless LPA2 is configured at HYP as well. This means kvm_lpa2_is_enabled() is not the right condition to test when setting TCR_EL2.DS, as it will return false if LPA2 is only available for stage 1 but not for stage 2. Similary, programming TCR_EL2.PS based on a limited IPA range due to lack of stage2 LPA2 support could potentially result in problems. So use lpa2_is_enabled() instead, and set the PS field according to the host's IPS, which is capped at 48 bits if LPA2 support is absent or disabled. Whether or not we can make meaningful use of such a configuration is a different question. Cc: stable@vger.kernel.org Signed-off-by: Ard Biesheuvel Acked-by: Marc Zyngier Link: https://lore.kernel.org/r/20241212081841.2168124-11-ardb+git@google.com Signed-off-by: Will Deacon Signed-off-by: Greg Kroah-Hartman Signed-off-by: Noah Wager Signed-off-by: Mehmet Basaran --- arch/arm64/kvm/arm.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 3ca8330cc2a8..5496250f6dc2 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -1859,8 +1859,7 @@ static int kvm_init_vector_slots(void) static void __init cpu_prepare_hyp_mode(int cpu, u32 hyp_va_bits) { struct kvm_nvhe_init_params *params = per_cpu_ptr_nvhe_sym(kvm_init_params, cpu); - u64 mmfr0 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1); - unsigned long tcr; + unsigned long tcr, ips; /* * Calculate the raw per-cpu offset without a translation from the @@ -1874,6 +1873,7 @@ static void __init cpu_prepare_hyp_mode(int cpu, u32 hyp_va_bits) params->mair_el2 = read_sysreg(mair_el1); tcr = read_sysreg(tcr_el1); + ips = FIELD_GET(TCR_IPS_MASK, tcr); if (cpus_have_final_cap(ARM64_KVM_HVHE)) { tcr |= TCR_EPD1_MASK; } else { @@ -1883,8 +1883,8 @@ static void __init cpu_prepare_hyp_mode(int cpu, u32 hyp_va_bits) tcr &= ~TCR_T0SZ_MASK; tcr |= TCR_T0SZ(hyp_va_bits); tcr &= ~TCR_EL2_PS_MASK; - tcr |= FIELD_PREP(TCR_EL2_PS_MASK, kvm_get_parange(mmfr0)); - if (kvm_lpa2_is_enabled()) + tcr |= FIELD_PREP(TCR_EL2_PS_MASK, ips); + if (lpa2_is_enabled()) tcr |= TCR_EL2_DS; params->tcr_el2 = tcr;