[PATCH v3 3/5] x86/pvh: Omit needless clearing of phys_base

From: Ard Biesheuvel
Date: Wed Oct 09 2024 - 12:22:17 EST


From: Ard Biesheuvel <ardb@xxxxxxxxxx>

Since commit

d9ec1158056b ("x86/boot/64: Use RIP_REL_REF() to assign 'phys_base'")

phys_base is assigned directly rather than added to, so it is no longer
necessary to clear it after use.

Reviewed-by: Jason Andryuk <jason.andryuk@xxxxxxx>
Tested-by: Jason Andryuk <jason.andryuk@xxxxxxx>
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
---
arch/x86/platform/pvh/head.S | 7 -------
1 file changed, 7 deletions(-)

diff --git a/arch/x86/platform/pvh/head.S b/arch/x86/platform/pvh/head.S
index 5a196fb3ebd8..7ca51a4da217 100644
--- a/arch/x86/platform/pvh/head.S
+++ b/arch/x86/platform/pvh/head.S
@@ -180,13 +180,6 @@ SYM_CODE_START_LOCAL(pvh_start_xen)
ANNOTATE_RETPOLINE_SAFE
call *%rax

- /*
- * Clear phys_base. __startup_64 will *add* to its value,
- * so reset to 0.
- */
- xor %rbx, %rbx
- movq %rbx, phys_base(%rip)
-
/* startup_64 expects boot_params in %rsi. */
lea pvh_bootparams(%rip), %rsi
jmp startup_64
--
2.47.0.rc0.187.ge670bccf7e-goog