From: Suzuki K Poulose <suzuki.poulose@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org,
marc.zyngier@arm.com, cdall@kernel.org, eric.auger@redhat.com,
pbonzini@redhat.com, rkrcmar@redhat.com, will.deacon@arm.com,
catalin.marinas@arm.com, james.morse@arm.com,
dave.martin@arm.com, julien.grall@arm.com,
linux-kernel@vger.kernel.org, suzuki.poulose@arm.com
Subject: [PATCH v5 17/18] kvm: arm64: Limit the minimum number of page table levels
Date: Mon, 17 Sep 2018 11:41:39 +0100 [thread overview]
Message-ID: <20180917104144.19188-18-suzuki.poulose@arm.com> (raw)
In-Reply-To: <20180917104144.19188-1-suzuki.poulose@arm.com>
Since we are about to remove the lower limit on the IPA size,
make sure that we do not go to 1 level page table (e.g, with
32bit IPA on 64K host with concatenation) to avoid splitting
the host PMD huge pages at stage2.
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Christoffer Dall <cdall@kernel.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
arch/arm64/include/asm/stage2_pgtable.h | 8 +++++++-
arch/arm64/kvm/reset.c | 12 +++++++++++-
2 files changed, 18 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/include/asm/stage2_pgtable.h b/arch/arm64/include/asm/stage2_pgtable.h
index 352ec4158fdf..6a56fdff0823 100644
--- a/arch/arm64/include/asm/stage2_pgtable.h
+++ b/arch/arm64/include/asm/stage2_pgtable.h
@@ -72,8 +72,14 @@
/*
* The number of PTRS across all concatenated stage2 tables given by the
* number of bits resolved at the initial level.
+ * If we force more number of levels than necessary, we may have
+ * stage2_pgdir_shift > IPA, in which case, stage2_pgd_ptrs will have
+ * one entry.
*/
-#define __s2_pgd_ptrs(ipa, lvls) (1 << ((ipa) - pt_levels_pgdir_shift((lvls))))
+#define pgd_ptrs_shift(ipa, pgdir_shift) \
+ ((ipa) > (pgdir_shift) ? ((ipa) - (pgdir_shift)) : 0)
+#define __s2_pgd_ptrs(ipa, lvls) \
+ (1 << (pgd_ptrs_shift((ipa), pt_levels_pgdir_shift(lvls))))
#define __s2_pgd_size(ipa, lvls) (__s2_pgd_ptrs((ipa), (lvls)) * sizeof(pgd_t))
#define stage2_pgd_ptrs(kvm) __s2_pgd_ptrs(kvm_phys_shift(kvm), kvm_stage2_levels(kvm))
diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
index 76972b19bdd7..0393bb974b23 100644
--- a/arch/arm64/kvm/reset.c
+++ b/arch/arm64/kvm/reset.c
@@ -190,10 +190,19 @@ int kvm_arm_config_vm(struct kvm *kvm, unsigned long type)
{
u64 vtcr = VTCR_EL2_FLAGS;
u64 parange;
+ u8 lvls;
if (type)
return -EINVAL;
+ /*
+ * Use a minimum 2 level page table to prevent splitting
+ * host PMD huge pages at stage2.
+ */
+ lvls = stage2_pgtable_levels(KVM_PHYS_SHIFT);
+ if (lvls < 2)
+ lvls = 2;
+
parange = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1) & 7;
if (parange > ID_AA64MMFR0_PARANGE_MAX)
parange = ID_AA64MMFR0_PARANGE_MAX;
@@ -210,7 +219,8 @@ int kvm_arm_config_vm(struct kvm *kvm, unsigned long type)
vtcr |= (kvm_get_vmid_bits() == 16) ?
VTCR_EL2_VS_16BIT :
VTCR_EL2_VS_8BIT;
- vtcr |= VTCR_EL2_LVLS_TO_SL0(stage2_pgtable_levels(KVM_PHYS_SHIFT));
+
+ vtcr |= VTCR_EL2_LVLS_TO_SL0(lvls);
vtcr |= VTCR_EL2_T0SZ(KVM_PHYS_SHIFT);
kvm->arch.vtcr = vtcr;
--
2.19.0
next prev parent reply other threads:[~2018-09-17 10:43 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-17 10:41 [PATCH v5 00/18] kvm: arm64: Dynamic IPA and 52bit IPA Suzuki K Poulose
2018-09-17 10:41 ` [PATCH v5 01/18] kvm: arm/arm64: Fix stage2_flush_memslot for 4 level page table Suzuki K Poulose
2018-09-17 10:41 ` [PATCH v5 02/18] kvm: arm/arm64: Remove spurious WARN_ON Suzuki K Poulose
2018-09-17 10:41 ` [PATCH v5 03/18] kvm: arm64: Add helper for loading the stage2 setting for a VM Suzuki K Poulose
2018-09-17 10:41 ` [PATCH v5 04/18] arm64: Add a helper for PARange to physical shift conversion Suzuki K Poulose
2018-09-17 10:41 ` [PATCH v5 05/18] kvm: arm64: Clean up VTCR_EL2 initialisation Suzuki K Poulose
2018-09-17 10:41 ` [PATCH v5 06/18] kvm: arm/arm64: Allow arch specific configurations for VM Suzuki K Poulose
2018-09-20 10:22 ` Auger Eric
2018-09-17 10:41 ` [PATCH v5 07/18] kvm: arm64: Configure VTCR_EL2 per VM Suzuki K Poulose
2018-09-20 10:21 ` Auger Eric
2018-09-20 10:38 ` Suzuki K Poulose
2018-09-17 10:41 ` [PATCH v5 08/18] kvm: arm/arm64: Prepare for VM specific stage2 translations Suzuki K Poulose
2018-09-20 14:07 ` Auger Eric
2018-09-17 10:41 ` [PATCH v5 09/18] kvm: arm64: Prepare for dynamic stage2 page table layout Suzuki K Poulose
2018-09-17 10:41 ` [PATCH v5 10/18] kvm: arm64: Make stage2 page table layout dynamic Suzuki K Poulose
2018-09-20 14:07 ` Auger Eric
2018-09-17 10:41 ` [PATCH v5 11/18] kvm: arm64: Dynamic configuration of VTTBR mask Suzuki K Poulose
2018-09-20 14:07 ` Auger Eric
2018-09-20 15:22 ` Suzuki K Poulose
2018-09-25 11:56 ` Auger Eric
2018-09-17 10:41 ` [PATCH v5 12/18] kvm: arm64: Configure VTCR_EL2.SL0 per VM Suzuki K Poulose
2018-09-20 14:25 ` Auger Eric
2018-09-20 15:25 ` Suzuki K Poulose
2018-09-17 10:41 ` [PATCH v5 13/18] kvm: arm64: Switch to per VM IPA limit Suzuki K Poulose
2018-09-17 10:41 ` [PATCH v5 14/18] vgic: Add support for 52bit guest physical address Suzuki K Poulose
2018-09-21 14:57 ` Auger Eric
2018-09-25 10:49 ` Suzuki K Poulose
2018-09-17 10:41 ` [PATCH v5 15/18] kvm: arm64: Add 52bit support for PAR to HPFAR conversoin Suzuki K Poulose
2018-09-25 9:59 ` Auger Eric
2018-09-17 10:41 ` [PATCH v5 16/18] kvm: arm64: Set a limit on the IPA size Suzuki K Poulose
2018-09-25 9:59 ` Auger Eric
2018-09-25 11:10 ` Suzuki K Poulose
2018-09-17 10:41 ` Suzuki K Poulose [this message]
2018-09-25 10:00 ` [PATCH v5 17/18] kvm: arm64: Limit the minimum number of page table levels Auger Eric
2018-09-25 10:25 ` Suzuki K Poulose
2018-09-17 10:41 ` [PATCH v5 18/18] kvm: arm64: Allow tuning the physical address size for VM Suzuki K Poulose
2018-09-17 14:20 ` Peter Maydell
2018-09-17 14:43 ` Suzuki K Poulose
2018-09-18 1:55 ` Peter Maydell
2018-09-18 15:16 ` Suzuki K Poulose
2018-09-18 15:36 ` Peter Maydell
2018-09-18 16:27 ` Suzuki K Poulose
2018-09-18 17:15 ` Peter Maydell
2018-09-19 10:03 ` Suzuki K Poulose
2018-09-25 10:00 ` Auger Eric
2018-09-25 10:24 ` Suzuki K Poulose
2018-09-17 10:41 ` [kvmtool PATCH v5 19/18] kvmtool: Allow backends to run checks on the KVM device fd Suzuki K Poulose
2018-09-17 10:41 ` [kvmtool PATCH v5 20/18] kvmtool: arm64: Add support for guest physical address size Suzuki K Poulose
2018-09-17 10:41 ` [kvmtool PATCH v5 21/18] kvmtool: arm64: Switch memory layout Suzuki K Poulose
2018-09-17 10:41 ` [kvmtool PATCH v5 22/18] kvmtool: arm: Add support for creating VM with PA size Suzuki K Poulose
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