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authorKalesh Singh <kaleshsingh@google.com>2022-07-26 10:37:46 +0300
committerMarc Zyngier <maz@kernel.org>2022-07-26 12:50:12 +0300
commit6928bcc84bc4bd9a24a1cb1986418c3de76e1d99 (patch)
tree998aa50f0f6d9954e2155c5ef20a2b19e46f25c3 /arch/arm64/include
parent72adac1bd234002a65cef738e0eebfd6c2ce2e30 (diff)
downloadlinux-6928bcc84bc4bd9a24a1cb1986418c3de76e1d99.tar.xz
KVM: arm64: Allocate shared pKVM hyp stacktrace buffers
In protected nVHE mode the host cannot directly access hypervisor memory, so we will dump the hypervisor stacktrace to a shared buffer with the host. The minimum size for the buffer required, assuming the min frame size of [x29, x30] (2 * sizeof(long)), is half the combined size of the hypervisor and overflow stacks plus an additional entry to delimit the end of the stacktrace. The stacktrace buffers are used later in the series to dump the nVHE hypervisor stacktrace when using protected-mode. Signed-off-by: Kalesh Singh <kaleshsingh@google.com> Reviewed-by: Fuad Tabba <tabba@google.com> Tested-by: Fuad Tabba <tabba@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220726073750.3219117-14-kaleshsingh@google.com
Diffstat (limited to 'arch/arm64/include')
-rw-r--r--arch/arm64/include/asm/memory.h8
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index 0af70d9abede..cab80a9a4086 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -114,6 +114,14 @@
#define OVERFLOW_STACK_SIZE SZ_4K
/*
+ * With the minimum frame size of [x29, x30], exactly half the combined
+ * sizes of the hyp and overflow stacks is the maximum size needed to
+ * save the unwinded stacktrace; plus an additional entry to delimit the
+ * end.
+ */
+#define NVHE_STACKTRACE_SIZE ((OVERFLOW_STACK_SIZE + PAGE_SIZE) / 2 + sizeof(long))
+
+/*
* Alignment of kernel segments (e.g. .text, .data).
*
* 4 KB granule: 16 level 3 entries, with contiguous bit