From: Anshuman Khandual <anshuman.khandual@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: Anshuman Khandual <anshuman.khandual@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
linux-kernel@vger.kernel.org, Marc Zyngier <maz@kernel.org>,
Will Deacon <will@kernel.org>,
kvmarm@lists.cs.columbia.edu
Subject: [PATCH V3] arm64/cpufeature: Validate hypervisor capabilities during CPU hotplug
Date: Tue, 12 May 2020 07:27:27 +0530 [thread overview]
Message-ID: <1589248647-22925-1-git-send-email-anshuman.khandual@arm.com> (raw)
This validates hypervisor capabilities like VMID width, IPA range for any
hot plug CPU against system finalized values. KVM's view of the IPA space
is used while allowing a given CPU to come up. While here, it factors out
get_vmid_bits() for general use.
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: kvmarm@lists.cs.columbia.edu
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Marc Zyngier <maz@kernel.org>
Suggested-by: Suzuki Poulose <suzuki.poulose@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
Changes in V3:
- Dropped "#ifdef CONFIG_KVM_ARM_HOST" per Marc
- Dropped ID_AA64MMFR0_PARANGE_MASK (for now)
- Updated the commit message per Marc
Changes in V2: (https://patchwork.kernel.org/patch/11535359/)
- Added is_hyp_mode_available() check per Marc
- Moved verify_kvm_capabilities() into cpufeature.c per Marc
- Added helper get_kvm_ipa_limit() to fetch kvm_ipa_limit per Marc
- Renamed kvm as hyp including the commit message per Marc
Changes in V1: (https://patchwork.kernel.org/patch/11532565/)
arch/arm64/include/asm/cpufeature.h | 18 ++++++++++++++++
arch/arm64/include/asm/kvm_mmu.h | 2 +-
arch/arm64/kernel/cpufeature.c | 33 +++++++++++++++++++++++++++++
arch/arm64/kvm/reset.c | 5 +++++
4 files changed, 57 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index afe08251ff95..1291ad5a9ccb 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -745,6 +745,24 @@ static inline bool cpu_has_hw_af(void)
extern bool cpu_has_amu_feat(int cpu);
#endif
+static inline unsigned int get_vmid_bits(u64 mmfr1)
+{
+ int vmid_bits;
+
+ vmid_bits = cpuid_feature_extract_unsigned_field(mmfr1,
+ ID_AA64MMFR1_VMIDBITS_SHIFT);
+ if (vmid_bits == ID_AA64MMFR1_VMIDBITS_16)
+ return 16;
+
+ /*
+ * Return the default here even if any reserved
+ * value is fetched from the system register.
+ */
+ return 8;
+}
+
+u32 get_kvm_ipa_limit(void);
+
#endif /* __ASSEMBLY__ */
#endif
diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index 30b0e8d6b895..a7137e144b97 100644
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -416,7 +416,7 @@ static inline unsigned int kvm_get_vmid_bits(void)
{
int reg = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1);
- return (cpuid_feature_extract_unsigned_field(reg, ID_AA64MMFR1_VMIDBITS_SHIFT) == 2) ? 16 : 8;
+ return get_vmid_bits(reg);
}
/*
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 9fac745aa7bb..30917fe7942a 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -2181,6 +2181,36 @@ static void verify_sve_features(void)
/* Add checks on other ZCR bits here if necessary */
}
+#ifdef CONFIG_KVM_ARM_HOST
+void verify_hyp_capabilities(void)
+{
+ u64 safe_mmfr1, mmfr0, mmfr1;
+ int parange, ipa_max;
+ unsigned int safe_vmid_bits, vmid_bits;
+
+ safe_mmfr1 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1);
+ mmfr0 = read_cpuid(ID_AA64MMFR0_EL1);
+ mmfr1 = read_cpuid(ID_AA64MMFR1_EL1);
+
+ /* Verify VMID bits */
+ safe_vmid_bits = get_vmid_bits(safe_mmfr1);
+ vmid_bits = get_vmid_bits(mmfr1);
+ if (vmid_bits < safe_vmid_bits) {
+ pr_crit("CPU%d: VMID width mismatch\n", smp_processor_id());
+ cpu_die_early();
+ }
+
+ /* Verify IPA range */
+ parange = mmfr0 & 0x7;
+ ipa_max = id_aa64mmfr0_parange_to_phys_shift(parange);
+ if (ipa_max < get_kvm_ipa_limit()) {
+ pr_crit("CPU%d: IPA range mismatch\n", smp_processor_id());
+ cpu_die_early();
+ }
+}
+#else /* !CONFIG_KVM_ARM_HOST */
+static inline void verify_hyp_capabilities(void) { }
+#endif /* CONFIG_KVM_ARM_HOST */
/*
* Run through the enabled system capabilities and enable() it on this CPU.
@@ -2206,6 +2236,9 @@ static void verify_local_cpu_capabilities(void)
if (system_supports_sve())
verify_sve_features();
+
+ if (is_hyp_mode_available())
+ verify_hyp_capabilities();
}
void check_local_cpu_capabilities(void)
diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
index 30b7ea680f66..841b492ff334 100644
--- a/arch/arm64/kvm/reset.c
+++ b/arch/arm64/kvm/reset.c
@@ -340,6 +340,11 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
return ret;
}
+u32 get_kvm_ipa_limit(void)
+{
+ return kvm_ipa_limit;
+}
+
void kvm_set_ipa_limit(void)
{
unsigned int ipa_max, pa_max, va_max, parange;
--
2.20.1
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
next reply other threads:[~2020-05-12 1:58 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-12 1:57 Anshuman Khandual [this message]
2020-05-20 17:54 ` [PATCH V3] arm64/cpufeature: Validate hypervisor capabilities during CPU hotplug Will Deacon
2020-05-21 0:48 ` Anshuman Khandual
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1589248647-22925-1-git-send-email-anshuman.khandual@arm.com \
--to=anshuman.khandual@arm.com \
--cc=catalin.marinas@arm.com \
--cc=kvmarm@lists.cs.columbia.edu \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=maz@kernel.org \
--cc=will@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).