From: Kalesh Singh <kaleshsingh@google.com>
To: maz@kernel.org, mark.rutland@arm.com, broonie@kernel.org,
madvenka@linux.microsoft.com, tabba@google.com
Cc: will@kernel.org, qperret@google.com, kaleshsingh@google.com,
james.morse@arm.com, alexandru.elisei@arm.com,
suzuki.poulose@arm.com, catalin.marinas@arm.com,
andreyknvl@gmail.com, vincenzo.frascino@arm.com,
mhiramat@kernel.org, ast@kernel.org, drjones@redhat.com,
wangkefeng.wang@huawei.com, elver@google.com, keirf@google.com,
yuzenghui@huawei.com, ardb@kernel.org, oupton@google.com,
linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org,
android-mm@google.com, kernel-team@android.com
Subject: [PATCH v5 15/17] KVM: arm64: Implement non-protected nVHE hyp stack unwinder
Date: Wed, 20 Jul 2022 22:57:26 -0700 [thread overview]
Message-ID: <20220721055728.718573-16-kaleshsingh@google.com> (raw)
In-Reply-To: <20220721055728.718573-1-kaleshsingh@google.com>
Implements the common framework necessary for unwind() to work
for non-protected nVHE mode:
- on_accessible_stack()
- on_overflow_stack()
- unwind_next()
Non-protected nVHE unwind() is used to unwind and dump the hypervisor
stacktrace by the host in EL1
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
---
Changes in v5:
- Use regular comments instead of doc comments, per Fuad
arch/arm64/include/asm/stacktrace/nvhe.h | 67 +++++++++++++++++++++++-
arch/arm64/kvm/arm.c | 2 +-
2 files changed, 66 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/include/asm/stacktrace/nvhe.h b/arch/arm64/include/asm/stacktrace/nvhe.h
index c3688e717136..7a6e761aa443 100644
--- a/arch/arm64/include/asm/stacktrace/nvhe.h
+++ b/arch/arm64/include/asm/stacktrace/nvhe.h
@@ -120,15 +120,78 @@ NOKPROBE_SYMBOL(unwind_next);
* (by the host in EL1).
*/
+DECLARE_KVM_NVHE_PER_CPU(unsigned long [PAGE_SIZE/sizeof(long)], overflow_stack);
+DECLARE_KVM_NVHE_PER_CPU(struct kvm_nvhe_stacktrace_info, kvm_stacktrace_info);
+DECLARE_PER_CPU(unsigned long, kvm_arm_hyp_stack_page);
+
+/*
+ * kvm_nvhe_stack_kern_va - Convert KVM nVHE HYP stack addresses to a kernel VAs
+ *
+ * The nVHE hypervisor stack is mapped in the flexible 'private' VA range, to
+ * allow for guard pages below the stack. Consequently, the fixed offset address
+ * translation macros won't work here.
+ *
+ * The kernel VA is calculated as an offset from the kernel VA of the hypervisor
+ * stack base.
+ *
+ * Returns true on success and updates @addr to its corresponding kernel VA;
+ * otherwise returns false.
+ */
+static inline bool kvm_nvhe_stack_kern_va(unsigned long *addr,
+ enum stack_type type)
+{
+ struct kvm_nvhe_stacktrace_info *stacktrace_info;
+ unsigned long hyp_base, kern_base, hyp_offset;
+
+ stacktrace_info = this_cpu_ptr_nvhe_sym(kvm_stacktrace_info);
+
+ switch (type) {
+ case STACK_TYPE_HYP:
+ kern_base = (unsigned long)*this_cpu_ptr(&kvm_arm_hyp_stack_page);
+ hyp_base = (unsigned long)stacktrace_info->stack_base;
+ break;
+ case STACK_TYPE_OVERFLOW:
+ kern_base = (unsigned long)this_cpu_ptr_nvhe_sym(overflow_stack);
+ hyp_base = (unsigned long)stacktrace_info->overflow_stack_base;
+ break;
+ default:
+ return false;
+ }
+
+ hyp_offset = *addr - hyp_base;
+
+ *addr = kern_base + hyp_offset;
+
+ return true;
+}
+
static inline bool on_overflow_stack(unsigned long sp, unsigned long size,
struct stack_info *info)
{
- return false;
+ struct kvm_nvhe_stacktrace_info *stacktrace_info
+ = this_cpu_ptr_nvhe_sym(kvm_stacktrace_info);
+ unsigned long low = (unsigned long)stacktrace_info->overflow_stack_base;
+ unsigned long high = low + OVERFLOW_STACK_SIZE;
+
+ return on_stack(sp, size, low, high, STACK_TYPE_OVERFLOW, info);
+}
+
+static inline bool on_hyp_stack(unsigned long sp, unsigned long size,
+ struct stack_info *info)
+{
+ struct kvm_nvhe_stacktrace_info *stacktrace_info
+ = this_cpu_ptr_nvhe_sym(kvm_stacktrace_info);
+ unsigned long low = (unsigned long)stacktrace_info->stack_base;
+ unsigned long high = low + PAGE_SIZE;
+
+ return on_stack(sp, size, low, high, STACK_TYPE_HYP, info);
}
static inline int notrace unwind_next(struct unwind_state *state)
{
- return 0;
+ struct stack_info info;
+
+ return unwind_next_common(state, &info, kvm_nvhe_stack_kern_va);
}
NOKPROBE_SYMBOL(unwind_next);
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index a0188144a122..6a64293108c5 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -49,7 +49,7 @@ DEFINE_STATIC_KEY_FALSE(kvm_protected_mode_initialized);
DECLARE_KVM_HYP_PER_CPU(unsigned long, kvm_hyp_vector);
-static DEFINE_PER_CPU(unsigned long, kvm_arm_hyp_stack_page);
+DEFINE_PER_CPU(unsigned long, kvm_arm_hyp_stack_page);
unsigned long kvm_arm_hyp_percpu_base[NR_CPUS];
DECLARE_KVM_NVHE_PER_CPU(struct kvm_nvhe_init_params, kvm_init_params);
--
2.37.0.170.g444d1eabd0-goog
next prev parent reply other threads:[~2022-07-21 5:58 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-21 5:57 [PATCH v5 00/17] KVM nVHE Hypervisor stack unwinder Kalesh Singh
2022-07-21 5:57 ` [PATCH v5 01/17] arm64: stacktrace: Add shared header for common stack unwinding code Kalesh Singh
2022-07-21 5:57 ` [PATCH v5 02/17] arm64: stacktrace: Factor out on_accessible_stack_common() Kalesh Singh
2022-07-21 5:57 ` [PATCH v5 03/17] arm64: stacktrace: Factor out unwind_next_common() Kalesh Singh
2022-07-21 5:57 ` [PATCH v5 04/17] arm64: stacktrace: Handle frame pointer from different address spaces Kalesh Singh
2022-07-21 9:57 ` Fuad Tabba
2022-07-21 5:57 ` [PATCH v5 05/17] arm64: stacktrace: Factor out common unwind() Kalesh Singh
2022-07-25 14:05 ` Mark Brown
2022-07-21 5:57 ` [PATCH v5 06/17] arm64: stacktrace: Add description of stacktrace/common.h Kalesh Singh
2022-07-21 9:57 ` Fuad Tabba
2022-07-21 5:57 ` [PATCH v5 07/17] KVM: arm64: On stack overflow switch to hyp overflow_stack Kalesh Singh
2022-07-21 5:57 ` [PATCH v5 08/17] KVM: arm64: Add PROTECTED_NVHE_STACKTRACE Kconfig Kalesh Singh
2022-07-21 9:57 ` Fuad Tabba
2022-07-21 5:57 ` [PATCH v5 09/17] KVM: arm64: Allocate shared pKVM hyp stacktrace buffers Kalesh Singh
2022-07-21 9:57 ` Fuad Tabba
2022-07-21 5:57 ` [PATCH v5 10/17] KVM: arm64: Stub implementation of pKVM HYP stack unwinder Kalesh Singh
2022-07-21 9:58 ` Fuad Tabba
2022-07-21 5:57 ` [PATCH v5 11/17] KVM: arm64: Stub implementation of non-protected nVHE " Kalesh Singh
2022-07-21 9:58 ` Fuad Tabba
2022-07-21 5:57 ` [PATCH v5 12/17] KVM: arm64: Save protected-nVHE (pKVM) hyp stacktrace Kalesh Singh
2022-07-21 9:58 ` Fuad Tabba
2022-07-22 15:33 ` Oliver Upton
2022-07-22 17:28 ` Kalesh Singh
2022-07-21 5:57 ` [PATCH v5 13/17] KVM: arm64: Prepare non-protected nVHE hypervisor stacktrace Kalesh Singh
2022-07-21 9:58 ` Fuad Tabba
2022-07-21 5:57 ` [PATCH v5 14/17] KVM: arm64: Implement protected nVHE hyp stack unwinder Kalesh Singh
2022-07-21 9:58 ` Fuad Tabba
2022-07-21 5:57 ` Kalesh Singh [this message]
2022-07-21 9:58 ` [PATCH v5 15/17] KVM: arm64: Implement non-protected " Fuad Tabba
2022-07-21 5:57 ` [PATCH v5 16/17] KVM: arm64: Introduce pkvm_dump_backtrace() Kalesh Singh
2022-07-21 9:59 ` Fuad Tabba
2022-07-22 11:16 ` Oliver Upton
2022-07-22 17:25 ` Kalesh Singh
2022-07-21 5:57 ` [PATCH v5 17/17] KVM: arm64: Introduce hyp_dump_backtrace() Kalesh Singh
2022-07-21 9:59 ` Fuad Tabba
2022-07-21 20:35 ` Oliver Upton
2022-07-22 0:01 ` Kalesh Singh
2022-07-21 9:55 ` [PATCH v5 00/17] KVM nVHE Hypervisor stack unwinder Fuad Tabba
2022-07-21 16:06 ` Kalesh Singh
2022-07-22 10:48 ` Oliver Upton
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