From: Kalesh Singh <kaleshsingh@google.com>
To: unlisted-recipients:; (no To-header on input)
Cc: will@kernel.org, maz@kernel.org, qperret@google.com,
tabba@google.com, surenb@google.com, kernel-team@android.com,
Kalesh Singh <kaleshsingh@google.com>,
James Morse <james.morse@arm.com>,
Alexandru Elisei <alexandru.elisei@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
Mark Brown <broonie@kernel.org>,
Masami Hiramatsu <mhiramat@kernel.org>,
Peter Collingbourne <pcc@google.com>,
"Madhavan T. Venkataraman" <madvenka@linux.microsoft.com>,
Stephen Boyd <swboyd@chromium.org>,
Andrew Walbran <qwandor@google.com>,
Andrew Scull <ascull@google.com>,
linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org
Subject: [PATCH v5 4/8] KVM: arm64: Add guard pages for pKVM (protected nVHE) hypervisor stack
Date: Mon, 7 Mar 2022 10:49:02 -0800 [thread overview]
Message-ID: <20220307184935.1704614-5-kaleshsingh@google.com> (raw)
In-Reply-To: <20220307184935.1704614-1-kaleshsingh@google.com>
Map the stack pages in the flexible private VA range and allocate
guard pages below the stack as unbacked VA space. The stack is aligned
so that any valid stack address has PAGE_SHIFT bit as 1 - this is used
for overflow detection (implemented in a subsequent patch in the series)
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
---
Changes in v5:
- Use a single allocation for stack and guard pages to ensure they
are contiguous, per Marc
Changes in v4:
- Replace IS_ERR_OR_NULL check with IS_ERR check now that
pkvm_alloc_private_va_range() returns an error for null
pointer, per Fuad
Changes in v3:
- Handle null ptr in IS_ERR_OR_NULL checks, per Mark
arch/arm64/kvm/hyp/nvhe/setup.c | 31 ++++++++++++++++++++++++++++---
1 file changed, 28 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/kvm/hyp/nvhe/setup.c b/arch/arm64/kvm/hyp/nvhe/setup.c
index 27af337f9fea..4bec3069b234 100644
--- a/arch/arm64/kvm/hyp/nvhe/setup.c
+++ b/arch/arm64/kvm/hyp/nvhe/setup.c
@@ -99,17 +99,42 @@ static int recreate_hyp_mappings(phys_addr_t phys, unsigned long size,
return ret;
for (i = 0; i < hyp_nr_cpus; i++) {
+ struct kvm_nvhe_init_params *params = per_cpu_ptr(&kvm_init_params, i);
+ unsigned long hyp_addr;
+
start = (void *)kern_hyp_va(per_cpu_base[i]);
end = start + PAGE_ALIGN(hyp_percpu_size);
ret = pkvm_create_mappings(start, end, PAGE_HYP);
if (ret)
return ret;
- end = (void *)per_cpu_ptr(&kvm_init_params, i)->stack_hyp_va;
- start = end - PAGE_SIZE;
- ret = pkvm_create_mappings(start, end, PAGE_HYP);
+ /*
+ * Allocate a contiguous HYP private VA range for the stack
+ * and guard page. The allocation is also aligned based on
+ * the order of its size.
+ */
+ hyp_addr = pkvm_alloc_private_va_range(PAGE_SIZE * 2);
+ if (IS_ERR((void *)hyp_addr))
+ return PTR_ERR((void *)hyp_addr);
+
+ /*
+ * Since the stack grows downwards, map the stack to the page
+ * at the higher address and leave the lower guard page
+ * unbacked.
+ *
+ * Any valid stack address now has the PAGE_SHIFT bit as 1
+ * and addresses corresponding to the guard page have the
+ * PAGE_SHIFT bit as 0 - this is used for overflow detection.
+ */
+ hyp_spin_lock(&pkvm_pgd_lock);
+ ret = kvm_pgtable_hyp_map(&pkvm_pgtable, hyp_addr + PAGE_SIZE,
+ PAGE_SIZE, params->stack_pa, PAGE_HYP);
+ hyp_spin_unlock(&pkvm_pgd_lock);
if (ret)
return ret;
+
+ /* Update stack_hyp_va to end of the stack's private VA range */
+ params->stack_hyp_va = hyp_addr + (2 * PAGE_SIZE);
}
/*
--
2.35.1.616.g0bdcbb4464-goog
WARNING: multiple messages have this Message-ID (diff)
From: Kalesh Singh <kaleshsingh@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
will@kernel.org, kvmarm@lists.cs.columbia.edu,
Andrew Walbran <qwandor@google.com>,
maz@kernel.org,
"Madhavan T. Venkataraman" <madvenka@linux.microsoft.com>,
kernel-team@android.com, Stephen Boyd <swboyd@chromium.org>,
surenb@google.com, Mark Brown <broonie@kernel.org>,
Peter Collingbourne <pcc@google.com>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org,
Masami Hiramatsu <mhiramat@kernel.org>
Subject: [PATCH v5 4/8] KVM: arm64: Add guard pages for pKVM (protected nVHE) hypervisor stack
Date: Mon, 7 Mar 2022 10:49:02 -0800 [thread overview]
Message-ID: <20220307184935.1704614-5-kaleshsingh@google.com> (raw)
In-Reply-To: <20220307184935.1704614-1-kaleshsingh@google.com>
Map the stack pages in the flexible private VA range and allocate
guard pages below the stack as unbacked VA space. The stack is aligned
so that any valid stack address has PAGE_SHIFT bit as 1 - this is used
for overflow detection (implemented in a subsequent patch in the series)
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
---
Changes in v5:
- Use a single allocation for stack and guard pages to ensure they
are contiguous, per Marc
Changes in v4:
- Replace IS_ERR_OR_NULL check with IS_ERR check now that
pkvm_alloc_private_va_range() returns an error for null
pointer, per Fuad
Changes in v3:
- Handle null ptr in IS_ERR_OR_NULL checks, per Mark
arch/arm64/kvm/hyp/nvhe/setup.c | 31 ++++++++++++++++++++++++++++---
1 file changed, 28 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/kvm/hyp/nvhe/setup.c b/arch/arm64/kvm/hyp/nvhe/setup.c
index 27af337f9fea..4bec3069b234 100644
--- a/arch/arm64/kvm/hyp/nvhe/setup.c
+++ b/arch/arm64/kvm/hyp/nvhe/setup.c
@@ -99,17 +99,42 @@ static int recreate_hyp_mappings(phys_addr_t phys, unsigned long size,
return ret;
for (i = 0; i < hyp_nr_cpus; i++) {
+ struct kvm_nvhe_init_params *params = per_cpu_ptr(&kvm_init_params, i);
+ unsigned long hyp_addr;
+
start = (void *)kern_hyp_va(per_cpu_base[i]);
end = start + PAGE_ALIGN(hyp_percpu_size);
ret = pkvm_create_mappings(start, end, PAGE_HYP);
if (ret)
return ret;
- end = (void *)per_cpu_ptr(&kvm_init_params, i)->stack_hyp_va;
- start = end - PAGE_SIZE;
- ret = pkvm_create_mappings(start, end, PAGE_HYP);
+ /*
+ * Allocate a contiguous HYP private VA range for the stack
+ * and guard page. The allocation is also aligned based on
+ * the order of its size.
+ */
+ hyp_addr = pkvm_alloc_private_va_range(PAGE_SIZE * 2);
+ if (IS_ERR((void *)hyp_addr))
+ return PTR_ERR((void *)hyp_addr);
+
+ /*
+ * Since the stack grows downwards, map the stack to the page
+ * at the higher address and leave the lower guard page
+ * unbacked.
+ *
+ * Any valid stack address now has the PAGE_SHIFT bit as 1
+ * and addresses corresponding to the guard page have the
+ * PAGE_SHIFT bit as 0 - this is used for overflow detection.
+ */
+ hyp_spin_lock(&pkvm_pgd_lock);
+ ret = kvm_pgtable_hyp_map(&pkvm_pgtable, hyp_addr + PAGE_SIZE,
+ PAGE_SIZE, params->stack_pa, PAGE_HYP);
+ hyp_spin_unlock(&pkvm_pgd_lock);
if (ret)
return ret;
+
+ /* Update stack_hyp_va to end of the stack's private VA range */
+ params->stack_hyp_va = hyp_addr + (2 * PAGE_SIZE);
}
/*
--
2.35.1.616.g0bdcbb4464-goog
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
WARNING: multiple messages have this Message-ID (diff)
From: Kalesh Singh <kaleshsingh@google.com>
Cc: will@kernel.org, maz@kernel.org, qperret@google.com,
tabba@google.com, surenb@google.com, kernel-team@android.com,
Kalesh Singh <kaleshsingh@google.com>,
James Morse <james.morse@arm.com>,
Alexandru Elisei <alexandru.elisei@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
Mark Brown <broonie@kernel.org>,
Masami Hiramatsu <mhiramat@kernel.org>,
Peter Collingbourne <pcc@google.com>,
"Madhavan T. Venkataraman" <madvenka@linux.microsoft.com>,
Stephen Boyd <swboyd@chromium.org>,
Andrew Walbran <qwandor@google.com>,
Andrew Scull <ascull@google.com>,
linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org
Subject: [PATCH v5 4/8] KVM: arm64: Add guard pages for pKVM (protected nVHE) hypervisor stack
Date: Mon, 7 Mar 2022 10:49:02 -0800 [thread overview]
Message-ID: <20220307184935.1704614-5-kaleshsingh@google.com> (raw)
In-Reply-To: <20220307184935.1704614-1-kaleshsingh@google.com>
Map the stack pages in the flexible private VA range and allocate
guard pages below the stack as unbacked VA space. The stack is aligned
so that any valid stack address has PAGE_SHIFT bit as 1 - this is used
for overflow detection (implemented in a subsequent patch in the series)
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
---
Changes in v5:
- Use a single allocation for stack and guard pages to ensure they
are contiguous, per Marc
Changes in v4:
- Replace IS_ERR_OR_NULL check with IS_ERR check now that
pkvm_alloc_private_va_range() returns an error for null
pointer, per Fuad
Changes in v3:
- Handle null ptr in IS_ERR_OR_NULL checks, per Mark
arch/arm64/kvm/hyp/nvhe/setup.c | 31 ++++++++++++++++++++++++++++---
1 file changed, 28 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/kvm/hyp/nvhe/setup.c b/arch/arm64/kvm/hyp/nvhe/setup.c
index 27af337f9fea..4bec3069b234 100644
--- a/arch/arm64/kvm/hyp/nvhe/setup.c
+++ b/arch/arm64/kvm/hyp/nvhe/setup.c
@@ -99,17 +99,42 @@ static int recreate_hyp_mappings(phys_addr_t phys, unsigned long size,
return ret;
for (i = 0; i < hyp_nr_cpus; i++) {
+ struct kvm_nvhe_init_params *params = per_cpu_ptr(&kvm_init_params, i);
+ unsigned long hyp_addr;
+
start = (void *)kern_hyp_va(per_cpu_base[i]);
end = start + PAGE_ALIGN(hyp_percpu_size);
ret = pkvm_create_mappings(start, end, PAGE_HYP);
if (ret)
return ret;
- end = (void *)per_cpu_ptr(&kvm_init_params, i)->stack_hyp_va;
- start = end - PAGE_SIZE;
- ret = pkvm_create_mappings(start, end, PAGE_HYP);
+ /*
+ * Allocate a contiguous HYP private VA range for the stack
+ * and guard page. The allocation is also aligned based on
+ * the order of its size.
+ */
+ hyp_addr = pkvm_alloc_private_va_range(PAGE_SIZE * 2);
+ if (IS_ERR((void *)hyp_addr))
+ return PTR_ERR((void *)hyp_addr);
+
+ /*
+ * Since the stack grows downwards, map the stack to the page
+ * at the higher address and leave the lower guard page
+ * unbacked.
+ *
+ * Any valid stack address now has the PAGE_SHIFT bit as 1
+ * and addresses corresponding to the guard page have the
+ * PAGE_SHIFT bit as 0 - this is used for overflow detection.
+ */
+ hyp_spin_lock(&pkvm_pgd_lock);
+ ret = kvm_pgtable_hyp_map(&pkvm_pgtable, hyp_addr + PAGE_SIZE,
+ PAGE_SIZE, params->stack_pa, PAGE_HYP);
+ hyp_spin_unlock(&pkvm_pgd_lock);
if (ret)
return ret;
+
+ /* Update stack_hyp_va to end of the stack's private VA range */
+ params->stack_hyp_va = hyp_addr + (2 * PAGE_SIZE);
}
/*
--
2.35.1.616.g0bdcbb4464-goog
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2022-03-07 18:51 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-07 18:48 [PATCH v5 0/8] KVM: arm64: Hypervisor stack enhancements Kalesh Singh
2022-03-07 18:48 ` Kalesh Singh
2022-03-07 18:48 ` Kalesh Singh
2022-03-07 18:48 ` [PATCH v5 1/8] KVM: arm64: Introduce hyp_alloc_private_va_range() Kalesh Singh
2022-03-07 18:48 ` Kalesh Singh
2022-03-07 18:48 ` Kalesh Singh
2022-03-08 20:21 ` Stephen Boyd
2022-03-08 20:21 ` Stephen Boyd
2022-03-08 20:21 ` Stephen Boyd
2022-03-08 23:09 ` Kalesh Singh
2022-03-08 23:09 ` Kalesh Singh
2022-03-08 23:09 ` Kalesh Singh
2022-03-09 16:50 ` Quentin Perret
2022-03-09 16:50 ` Quentin Perret
2022-03-09 16:50 ` Quentin Perret
2022-03-09 17:04 ` Kalesh Singh
2022-03-09 17:04 ` Kalesh Singh
2022-03-09 17:04 ` Kalesh Singh
2022-03-07 18:49 ` [PATCH v5 2/8] KVM: arm64: Introduce pkvm_alloc_private_va_range() Kalesh Singh
2022-03-07 18:49 ` Kalesh Singh
2022-03-07 18:49 ` Kalesh Singh
2022-03-07 18:49 ` [PATCH v5 3/8] KVM: arm64: Add guard pages for KVM nVHE hypervisor stack Kalesh Singh
2022-03-07 18:49 ` Kalesh Singh
2022-03-07 18:49 ` Kalesh Singh
2022-03-07 18:49 ` Kalesh Singh [this message]
2022-03-07 18:49 ` [PATCH v5 4/8] KVM: arm64: Add guard pages for pKVM (protected nVHE) " Kalesh Singh
2022-03-07 18:49 ` Kalesh Singh
2022-03-07 18:49 ` [PATCH v5 5/8] KVM: arm64: Detect and handle hypervisor stack overflows Kalesh Singh
2022-03-07 18:49 ` Kalesh Singh
2022-03-07 18:49 ` Kalesh Singh
2022-03-07 18:49 ` [PATCH v5 6/8] KVM: arm64: Add hypervisor overflow stack Kalesh Singh
2022-03-07 18:49 ` Kalesh Singh
2022-03-07 18:49 ` Kalesh Singh
2022-03-07 18:49 ` [PATCH v5 7/8] KVM: arm64: Unwind and dump nVHE HYP stacktrace Kalesh Singh
2022-03-07 18:49 ` Kalesh Singh
2022-03-07 18:49 ` Kalesh Singh
2022-03-07 18:49 ` [PATCH v5 8/8] KVM: arm64: Symbolize the nVHE HYP backtrace Kalesh Singh
2022-03-07 18:49 ` Kalesh Singh
2022-03-07 18:49 ` Kalesh Singh
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