From 7bab16a6075b7b94999666355ab532c3dabb94f9 Mon Sep 17 00:00:00 2001 From: Jamie Iles Date: Fri, 13 Nov 2020 15:04:06 +0000 Subject: [PATCH] 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 Signed-off-by: Marc Zyngier Acked-by: David Brazdil Cc: David Brazdil Cc: Marc Zyngier Cc: Will Deacon Link: https://lore.kernel.org/r/20201113150406.14314-1-jamie@nuviainc.com --- arch/arm64/kvm/hyp/nvhe/hyp.lds.S | 5 +++++ 1 file changed, 5 insertions(+) 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) } -- 2.11.0