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| author | Jamie Iles <jamie@nuviainc.com> | 2020-11-13 18:04:06 +0300 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2020-11-16 12:30:42 +0300 |
| commit | 7bab16a6075b7b94999666355ab532c3dabb94f9 (patch) | |
| tree | e4278fa28c3687e82251db6b941c213f297c2c4f /arch/arm64/kvm | |
| parent | ed4ffaf49bf9ce1002b516d8c6aa04937b7950bc (diff) | |
| download | linux-7bab16a6075b7b94999666355ab532c3dabb94f9.tar.xz | |
KVM: arm64: Correctly align nVHE percpu data
The nVHE percpu data is partially linked but the nVHE linker script did
not align the percpu section. The PERCPU_INPUT macro would then align
the data to a page boundary:
#define PERCPU_INPUT(cacheline) \
__per_cpu_start = .; \
*(.data..percpu..first) \
. = ALIGN(PAGE_SIZE); \
*(.data..percpu..page_aligned) \
. = ALIGN(cacheline); \
*(.data..percpu..read_mostly) \
. = ALIGN(cacheline); \
*(.data..percpu) \
*(.data..percpu..shared_aligned) \
PERCPU_DECRYPTED_SECTION \
__per_cpu_end = .;
but then when the final vmlinux linking happens the hypervisor percpu
data is included after page alignment and so the offsets potentially
don't match. On my build I saw that the .hyp.data..percpu section was
at address 0x20 and then the percpu data would begin at 0x1000 (because
of the page alignment in PERCPU_INPUT), but when linked into vmlinux,
everything would be shifted down by 0x20 bytes.
This manifests as one of the CPUs getting lost when running
kvm-unit-tests or starting any VM and subsequent soft lockup on a Cortex
A72 device.
Fixes: 30c953911c43 ("kvm: arm64: Set up hyp percpu data for nVHE")
Signed-off-by: Jamie Iles <jamie@nuviainc.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: David Brazdil <dbrazdil@google.com>
Cc: David Brazdil <dbrazdil@google.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20201113150406.14314-1-jamie@nuviainc.com
Diffstat (limited to 'arch/arm64/kvm')
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/hyp.lds.S | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp.lds.S b/arch/arm64/kvm/hyp/nvhe/hyp.lds.S index bb2d986ff696..a797abace13f 100644 --- a/arch/arm64/kvm/hyp/nvhe/hyp.lds.S +++ b/arch/arm64/kvm/hyp/nvhe/hyp.lds.S @@ -13,6 +13,11 @@ SECTIONS { HYP_SECTION(.text) + /* + * .hyp..data..percpu needs to be page aligned to maintain the same + * alignment for when linking into vmlinux. + */ + . = ALIGN(PAGE_SIZE); HYP_SECTION_NAME(.data..percpu) : { PERCPU_INPUT(L1_CACHE_BYTES) } |