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From: Uros Bizjak <ubizjak@gmail.com>
To: linux-hyperv@vger.kernel.org, x86@kernel.org,
	linux-kernel@vger.kernel.org
Cc: Uros Bizjak <ubizjak@gmail.com>, Wei Liu <wei.liu@kernel.org>,
	Michael Kelley <mhklinux@outlook.com>,
	"K. Y. Srinivasan" <kys@microsoft.com>,
	Haiyang Zhang <haiyangz@microsoft.com>,
	Dexuan Cui <decui@microsoft.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	"H. Peter Anvin" <hpa@zytor.com>
Subject: [PATCH v2 2/3] x86/hyperv: Use savesegment() instead of inline asm() to save segment registers
Date: Fri, 21 Nov 2025 15:14:10 +0100	[thread overview]
Message-ID: <20251121141437.205481-2-ubizjak@gmail.com> (raw)
In-Reply-To: <20251121141437.205481-1-ubizjak@gmail.com>

Use standard savesegment() utility macro to save segment registers.

Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Acked-by: Wei Liu <wei.liu@kernel.org>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
---
 arch/x86/hyperv/ivm.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/arch/x86/hyperv/ivm.c b/arch/x86/hyperv/ivm.c
index 651771534cae..7365d8f43181 100644
--- a/arch/x86/hyperv/ivm.c
+++ b/arch/x86/hyperv/ivm.c
@@ -25,6 +25,7 @@
 #include <asm/e820/api.h>
 #include <asm/desc.h>
 #include <asm/msr.h>
+#include <asm/segment.h>
 #include <uapi/asm/vmx.h>
 
 #ifdef CONFIG_AMD_MEM_ENCRYPT
@@ -315,16 +316,16 @@ int hv_snp_boot_ap(u32 apic_id, unsigned long start_ip, unsigned int cpu)
 	vmsa->gdtr.base = gdtr.address;
 	vmsa->gdtr.limit = gdtr.size;
 
-	asm volatile("movl %%es, %%eax;" : "=a" (vmsa->es.selector));
+	savesegment(es, vmsa->es.selector);
 	hv_populate_vmcb_seg(vmsa->es, vmsa->gdtr.base);
 
-	asm volatile("movl %%cs, %%eax;" : "=a" (vmsa->cs.selector));
+	savesegment(cs, vmsa->cs.selector);
 	hv_populate_vmcb_seg(vmsa->cs, vmsa->gdtr.base);
 
-	asm volatile("movl %%ss, %%eax;" : "=a" (vmsa->ss.selector));
+	savesegment(ss, vmsa->ss.selector);
 	hv_populate_vmcb_seg(vmsa->ss, vmsa->gdtr.base);
 
-	asm volatile("movl %%ds, %%eax;" : "=a" (vmsa->ds.selector));
+	savesegment(ds, vmsa->ds.selector);
 	hv_populate_vmcb_seg(vmsa->ds, vmsa->gdtr.base);
 
 	vmsa->efer = native_read_msr(MSR_EFER);
-- 
2.51.1


  reply	other threads:[~2025-11-21 14:15 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-11-21 14:14 [PATCH v2 1/3] x86: Use MOVL when reading segment registers Uros Bizjak
2025-11-21 14:14 ` Uros Bizjak [this message]
2025-11-21 14:14 ` [PATCH v2 3/3] x86/hyperv: Remove ASM_CALL_CONSTRAINT with VMMCALL insn Uros Bizjak
2025-11-22  0:06   ` H. Peter Anvin
2025-11-22  9:33     ` Uros Bizjak

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