From: Alexandru Elisei <alexandru.elisei@arm.com>
To: Marc Zyngier <maz@kernel.org>,
linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Andre Przywara <andre.przywara@arm.com>,
Christoffer Dall <christoffer.dall@arm.com>,
Dave Martin <Dave.Martin@arm.com>,
George Cherian <gcherian@marvell.com>,
James Morse <james.morse@arm.com>,
"Zengtao \(B\)" <prime.zeng@hisilicon.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
Jintack Lim <jintack@cs.columbia.edu>,
Julien Thierry <julien.thierry.kdev@gmail.com>
Subject: Re: [PATCH 01/26] KVM: arm64: Check advertised Stage-2 page size capability
Date: Thu, 7 May 2020 12:42:12 +0100 [thread overview]
Message-ID: <f2de215f-2ad4-da04-36ab-8932d35abba6@arm.com> (raw)
In-Reply-To: <20200422120050.3693593-2-maz@kernel.org>
Hi,
On 4/22/20 1:00 PM, Marc Zyngier wrote:
> With ARMv8.5-GTG, the hardware (or more likely a hypervisor) can
> advertise the supported Stage-2 page sizes.
>
> Let's check this at boot time.
>
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
> arch/arm64/include/asm/kvm_host.h | 2 +-
> arch/arm64/include/asm/sysreg.h | 3 +++
> arch/arm64/kernel/cpufeature.c | 8 +++++++
> arch/arm64/kvm/reset.c | 40 ++++++++++++++++++++++++++++---
> virt/kvm/arm/arm.c | 4 +---
> 5 files changed, 50 insertions(+), 7 deletions(-)
>
> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
> index 32c8a675e5a4a..7dd8fefa6aecd 100644
> --- a/arch/arm64/include/asm/kvm_host.h
> +++ b/arch/arm64/include/asm/kvm_host.h
> @@ -670,7 +670,7 @@ static inline int kvm_arm_have_ssbd(void)
> void kvm_vcpu_load_sysregs(struct kvm_vcpu *vcpu);
> void kvm_vcpu_put_sysregs(struct kvm_vcpu *vcpu);
>
> -void kvm_set_ipa_limit(void);
> +int kvm_set_ipa_limit(void);
>
> #define __KVM_HAVE_ARCH_VM_ALLOC
> struct kvm *kvm_arch_alloc_vm(void);
> diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
> index ebc6224328318..5d10c9148e844 100644
> --- a/arch/arm64/include/asm/sysreg.h
> +++ b/arch/arm64/include/asm/sysreg.h
> @@ -686,6 +686,9 @@
> #define ID_AA64ZFR0_SVEVER_SVE2 0x1
>
> /* id_aa64mmfr0 */
> +#define ID_AA64MMFR0_TGRAN4_2_SHIFT 40
> +#define ID_AA64MMFR0_TGRAN64_2_SHIFT 36
> +#define ID_AA64MMFR0_TGRAN16_2_SHIFT 32
> #define ID_AA64MMFR0_TGRAN4_SHIFT 28
> #define ID_AA64MMFR0_TGRAN64_SHIFT 24
> #define ID_AA64MMFR0_TGRAN16_SHIFT 20
> diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
> index 9fac745aa7bb2..9892a845d06c9 100644
> --- a/arch/arm64/kernel/cpufeature.c
> +++ b/arch/arm64/kernel/cpufeature.c
> @@ -208,6 +208,14 @@ static const struct arm64_ftr_bits ftr_id_aa64zfr0[] = {
> };
>
> static const struct arm64_ftr_bits ftr_id_aa64mmfr0[] = {
> + /*
> + * Page size not being supported at Stage-2 are not fatal. You
s/are not fatal/is not fatal
> + * just give up KVM if PAGE_SIZE isn't supported there. Go fix
> + * your favourite nesting hypervisor.
> + */
> + ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_EXACT, ID_AA64MMFR0_TGRAN4_2_SHIFT, 4, 1),
> + ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_EXACT, ID_AA64MMFR0_TGRAN64_2_SHIFT, 4, 1),
> + ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_EXACT, ID_AA64MMFR0_TGRAN16_2_SHIFT, 4, 1),
> /*
> * We already refuse to boot CPUs that don't support our configured
> * page size, so we can only detect mismatches for a page size other
> diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
> index 30b7ea680f66c..241db35a7ef4f 100644
> --- a/arch/arm64/kvm/reset.c
> +++ b/arch/arm64/kvm/reset.c
> @@ -9,6 +9,7 @@
> */
>
> #include <linux/errno.h>
> +#include <linux/bitfield.h>
> #include <linux/kernel.h>
> #include <linux/kvm_host.h>
> #include <linux/kvm.h>
> @@ -340,11 +341,42 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
> return ret;
> }
>
> -void kvm_set_ipa_limit(void)
> +int kvm_set_ipa_limit(void)
> {
> - unsigned int ipa_max, pa_max, va_max, parange;
> + unsigned int ipa_max, pa_max, va_max, parange, tgran_2;
> + u64 mmfr0 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1);
>
> - parange = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1) & 0x7;
> + /*
> + * Check with ARMv8.5-GTG that our PAGE_SIZE is supported at
> + * Stage-2. If not, things will stop very quickly.
> + */
> + switch (PAGE_SIZE) {
> + default:
> + case SZ_4K:
> + tgran_2 = ID_AA64MMFR0_TGRAN4_2_SHIFT;
> + break;
> + case SZ_16K:
> + tgran_2 = ID_AA64MMFR0_TGRAN16_2_SHIFT;
> + break;
> + case SZ_64K:
> + tgran_2 = ID_AA64MMFR0_TGRAN64_2_SHIFT;
> + break;
> + }
> +
> + switch (FIELD_GET(0xFUL << tgran_2, mmfr0)) {
> + default:
> + case 1:
> + kvm_err("PAGE_SIZE not supported at Stage-2, giving up\n");
> + return -EINVAL;
> + case 0:
> + kvm_debug("PAGE_SIZE supported at Stage-2 (default)\n");
> + break;
> + case 2:
> + kvm_debug("PAGE_SIZE supported at Stage-2 (advertised)\n");
> + break;
> + }
> +
> + parange = mmfr0 & 0x7;
> pa_max = id_aa64mmfr0_parange_to_phys_shift(parange);
>
> /* Clamp the IPA limit to the PA size supported by the kernel */
> @@ -378,6 +410,8 @@ void kvm_set_ipa_limit(void)
> "KVM IPA limit (%d bit) is smaller than default size\n", ipa_max);
> kvm_ipa_limit = ipa_max;
> kvm_info("IPA Size Limit: %dbits\n", kvm_ipa_limit);
> +
> + return 0;
> }
>
> /*
> diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
> index 48d0ec44ad77e..53b3ba9173ba7 100644
> --- a/virt/kvm/arm/arm.c
> +++ b/virt/kvm/arm/arm.c
> @@ -1387,9 +1387,7 @@ static inline void hyp_cpu_pm_exit(void)
>
> static int init_common_resources(void)
> {
> - kvm_set_ipa_limit();
> -
> - return 0;
> + return kvm_set_ipa_limit();
> }
>
> static int init_subsystems(void)
For what is worth, I've taken a look at the ARMv8.5-GTG spec and your patch looks
fine to me:
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Thanks,
Alex
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next prev parent reply other threads:[~2020-05-07 11:41 UTC|newest]
Thread overview: 78+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-22 12:00 [PATCH 00/26] KVM: arm64: Preliminary NV patches Marc Zyngier
2020-04-22 12:00 ` [PATCH 01/26] KVM: arm64: Check advertised Stage-2 page size capability Marc Zyngier
2020-04-22 13:40 ` Suzuki K Poulose
2020-04-22 14:07 ` Marc Zyngier
2020-04-22 14:14 ` Suzuki K Poulose
2020-05-07 11:42 ` Alexandru Elisei [this message]
2020-04-22 12:00 ` [PATCH 02/26] KVM: arm64: Move __load_guest_stage2 to kvm_mmu.h Marc Zyngier
2020-04-22 13:51 ` Suzuki K Poulose
2020-04-22 13:59 ` Marc Zyngier
2020-04-22 12:00 ` [PATCH 03/26] KVM: arm64: Factor out stage 2 page table data from struct kvm Marc Zyngier
2020-05-05 15:26 ` Andrew Scull
2020-05-05 16:32 ` Marc Zyngier
2020-05-05 17:23 ` Andrew Scull
2020-05-05 18:10 ` Marc Zyngier
2020-05-05 16:03 ` James Morse
2020-05-05 17:59 ` Marc Zyngier
2020-05-06 9:30 ` Marc Zyngier
2020-05-11 16:38 ` Alexandru Elisei
2020-05-12 11:17 ` James Morse
2020-05-12 15:47 ` Alexandru Elisei
2020-05-12 16:13 ` James Morse
2020-05-12 16:53 ` Alexandru Elisei
2020-05-27 8:41 ` Marc Zyngier
2020-05-27 8:45 ` Alexandru Elisei
2020-04-22 12:00 ` [PATCH 04/26] arm64: Detect the ARMv8.4 TTL feature Marc Zyngier
2020-04-27 15:55 ` Suzuki K Poulose
2020-04-22 12:00 ` [PATCH 05/26] arm64: Document SW reserved PTE/PMD bits in Stage-2 descriptors Marc Zyngier
2020-05-05 15:59 ` Andrew Scull
2020-05-06 9:39 ` Marc Zyngier
2020-05-06 10:11 ` Andrew Scull
2020-04-22 12:00 ` [PATCH 06/26] arm64: Add level-hinted TLB invalidation helper Marc Zyngier
2020-05-05 17:16 ` Andrew Scull
2020-05-06 8:05 ` Marc Zyngier
2020-04-22 12:00 ` [PATCH 07/26] KVM: arm64: Add a level hint to __kvm_tlb_flush_vmid_ipa Marc Zyngier
2020-05-07 15:08 ` Andrew Scull
2020-05-07 15:13 ` Marc Zyngier
2020-04-22 12:00 ` [PATCH 08/26] KVM: arm64: Use TTL hint in when invalidating stage-2 translations Marc Zyngier
2020-05-07 15:13 ` Andrew Scull
2020-05-12 12:04 ` James Morse
2020-05-13 9:06 ` Andrew Scull
2020-05-27 8:59 ` Marc Zyngier
2020-05-12 17:26 ` James Morse
2020-04-22 12:00 ` [PATCH 09/26] KVM: arm64: vgic-v3: Take cpu_if pointer directly instead of vcpu Marc Zyngier
2020-05-07 16:26 ` James Morse
2020-05-08 12:20 ` Marc Zyngier
2020-04-22 12:00 ` [PATCH 10/26] KVM: arm64: Refactor vcpu_{read,write}_sys_reg Marc Zyngier
2020-05-26 16:28 ` James Morse
2020-05-27 10:04 ` Marc Zyngier
2020-04-22 12:00 ` [PATCH 11/26] KVM: arm64: Add missing reset handlers for PMU emulation Marc Zyngier
2020-05-26 16:29 ` James Morse
2020-04-22 12:00 ` [PATCH 12/26] KVM: arm64: Move sysreg reset check to boot time Marc Zyngier
2020-04-22 12:00 ` [PATCH 13/26] KVM: arm64: Introduce accessor for ctxt->sys_reg Marc Zyngier
2020-04-22 12:00 ` [PATCH 14/26] KVM: arm64: hyp: Use ctxt_sys_reg/__vcpu_sys_reg instead of raw sys_regs access Marc Zyngier
2020-04-22 12:00 ` [PATCH 15/26] KVM: arm64: sve: Use __vcpu_sys_reg() " Marc Zyngier
2020-04-22 12:00 ` [PATCH 16/26] KVM: arm64: pauth: Use ctxt_sys_reg() " Marc Zyngier
2020-04-22 12:00 ` [PATCH 17/26] KVM: arm64: debug: " Marc Zyngier
2020-04-22 12:00 ` [PATCH 18/26] KVM: arm64: Don't use empty structures as CPU reset state Marc Zyngier
2020-04-24 4:07 ` Zenghui Yu
2020-04-24 7:45 ` Marc Zyngier
2020-04-28 1:34 ` Zengtao (B)
2020-04-22 12:00 ` [PATCH 19/26] KVM: arm64: Make struct kvm_regs userspace-only Marc Zyngier
2020-05-26 16:29 ` James Morse
2020-05-27 10:22 ` Marc Zyngier
2020-04-22 12:00 ` [PATCH 20/26] KVM: arm64: Move ELR_EL1 to the system register array Marc Zyngier
2020-05-26 16:29 ` James Morse
2020-05-27 10:36 ` Marc Zyngier
2020-04-22 12:00 ` [PATCH 21/26] KVM: arm64: Move SP_EL1 " Marc Zyngier
2020-05-26 16:29 ` James Morse
2020-04-22 12:00 ` [PATCH 22/26] KVM: arm64: Disintegrate SPSR array Marc Zyngier
2020-05-26 16:30 ` James Morse
2020-04-22 12:00 ` [PATCH 23/26] KVM: arm64: Move SPSR_EL1 to the system register array Marc Zyngier
2020-05-26 16:30 ` James Morse
2020-04-22 12:00 ` [PATCH 24/26] KVM: arm64: timers: Rename kvm_timer_sync_hwstate to kvm_timer_sync_user Marc Zyngier
2020-04-22 12:00 ` [PATCH 25/26] KVM: arm64: timers: Move timer registers to the sys_regs file Marc Zyngier
2020-04-22 12:00 ` [PATCH 26/26] KVM: arm64: Parametrize exception entry with a target EL Marc Zyngier
2020-05-19 10:44 ` Mark Rutland
2020-05-27 9:34 ` Marc Zyngier
2020-05-27 14:41 ` Mark Rutland
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