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authorJuergen Gross <jgross@suse.com>2023-05-02 14:09:19 +0200
committerBorislav Petkov (AMD) <bp@alien8.de>2023-06-01 15:04:32 +0200
commitc957f1f3c498bcce85c04e92e60afbae1fd10cde (patch)
tree41acc9b90b0678be4e98a5329f97ee41d83cf196 /arch/x86/hyperv
parent29055dc74287467bd7a053d60b4afe753832960d (diff)
x86/hyperv: Set MTRR state when running as SEV-SNP Hyper-V guest
In order to avoid mappings using the UC- cache attribute, set the MTRR state to use WB caching as the default. This is needed in order to cope with the fact that PAT is enabled, while MTRRs are not supported by the hypervisor. Fixes: 90b926e68f50 ("x86/pat: Fix pat_x_mtrr_type() for MTRR disabled case") Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20230502120931.20719-5-jgross@suse.com Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Diffstat (limited to 'arch/x86/hyperv')
-rw-r--r--arch/x86/hyperv/ivm.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86/hyperv/ivm.c b/arch/x86/hyperv/ivm.c
index cc92388b7a99..6f7c1b5606ad 100644
--- a/arch/x86/hyperv/ivm.c
+++ b/arch/x86/hyperv/ivm.c
@@ -17,6 +17,7 @@
#include <asm/mem_encrypt.h>
#include <asm/mshyperv.h>
#include <asm/hypervisor.h>
+#include <asm/mtrr.h>
#ifdef CONFIG_AMD_MEM_ENCRYPT
@@ -372,6 +373,9 @@ void __init hv_vtom_init(void)
x86_platform.guest.enc_cache_flush_required = hv_vtom_cache_flush_required;
x86_platform.guest.enc_tlb_flush_required = hv_vtom_tlb_flush_required;
x86_platform.guest.enc_status_change_finish = hv_vtom_set_host_visibility;
+
+ /* Set WB as the default cache mode. */
+ mtrr_overwrite_state(NULL, 0, MTRR_TYPE_WRBACK);
}
#endif /* CONFIG_AMD_MEM_ENCRYPT */