[RFCv2 07/16] x86/realmode: Share trampoline area if KVM memory protection enabled

From: Kirill A. Shutemov
Date: Tue Oct 20 2020 - 02:20:58 EST


If KVM memory protection is active, the trampoline area will need to be
in shared memory.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
---
arch/x86/realmode/init.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/x86/realmode/init.c b/arch/x86/realmode/init.c
index 1ed1208931e0..7392940a7f96 100644
--- a/arch/x86/realmode/init.c
+++ b/arch/x86/realmode/init.c
@@ -9,6 +9,7 @@
#include <asm/realmode.h>
#include <asm/tlbflush.h>
#include <asm/crash.h>
+#include <asm/kvm_para.h>

struct real_mode_header *real_mode_header;
u32 *trampoline_cr4_features;
@@ -55,11 +56,11 @@ static void __init setup_real_mode(void)
base = (unsigned char *)real_mode_header;

/*
- * If SME is active, the trampoline area will need to be in
- * decrypted memory in order to bring up other processors
+ * If SME or KVM memory protection is active, the trampoline area will
+ * need to be in decrypted memory in order to bring up other processors
* successfully. This is not needed for SEV.
*/
- if (sme_active())
+ if (sme_active() || kvm_mem_protected())
set_memory_decrypted((unsigned long)base, size >> PAGE_SHIFT);

memcpy(base, real_mode_blob, size);
--
2.26.2