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authorZhao Liu <zhao1.liu@intel.com>2022-10-20 16:38:20 +0800
committerWei Liu <wei.liu@kernel.org>2022-10-27 10:58:04 +0000
commit03b9a6e18d325ede28c6dc218cedda53969eb41b (patch)
treef65da7c7af8048f02da5cc2d35176af04c3a952d /arch/x86/hyperv/hv_init.c
parent247f34f7b80357943234f93f247a1ae6b6c3a740 (diff)
x86/hyperv: Remove BUG_ON() for kmap_local_page()
The commit 154fb14df7a3c ("x86/hyperv: Replace kmap() with kmap_local_page()") keeps the BUG_ON() to check if kmap_local_page() fails. But in fact, kmap_local_page() always returns a valid kernel address and won't return NULL here. It will BUG on its own if it fails. [1] So directly use memcpy_to_page() which creates local mapping to copy. [1]: https://lore.kernel.org/lkml/YztFEyUA48et0yTt@iweiny-mobl/ Suggested-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Suggested-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Zhao Liu <zhao1.liu@intel.com> Link: https://lore.kernel.org/r/20221020083820.2341088-1-zhao1.liu@linux.intel.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
Diffstat (limited to 'arch/x86/hyperv/hv_init.c')
-rw-r--r--arch/x86/hyperv/hv_init.c8
1 files changed, 3 insertions, 5 deletions
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index 29774126e931..d46f70522ddf 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -444,7 +444,7 @@ void __init hyperv_init(void)
if (hv_root_partition) {
struct page *pg;
- void *src, *dst;
+ void *src;
/*
* For the root partition, the hypervisor will set up its
@@ -459,13 +459,11 @@ void __init hyperv_init(void)
wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
pg = vmalloc_to_page(hv_hypercall_pg);
- dst = kmap_local_page(pg);
src = memremap(hypercall_msr.guest_physical_address << PAGE_SHIFT, PAGE_SIZE,
MEMREMAP_WB);
- BUG_ON(!(src && dst));
- memcpy(dst, src, HV_HYP_PAGE_SIZE);
+ BUG_ON(!src);
+ memcpy_to_page(pg, 0, src, HV_HYP_PAGE_SIZE);
memunmap(src);
- kunmap_local(dst);
} else {
hypercall_msr.guest_physical_address = vmalloc_to_pfn(hv_hypercall_pg);
wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);