hv: xsave: move assembler to individual function

Current code avoid the rule 88 S in MISRA-C, so move xsaves and xrstors
assembler to individual functions.

Tracked-On: #4436
Signed-off-by: Conghui Chen <conghui.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>

Author: conghuic23

hypervisor/arch/x86/guest/vcpu.c

@@ -729,22 +729,14 @@ void save_xsave_area(struct ext_context *ectx)
 {
 	ectx->xcr0 = read_xcr(0);
 	ectx->xss = msr_read(MSR_IA32_XSS);
-	asm volatile("xsaves %0"
-			: : "m" (ectx->xs_area),
-			"d" (UINT32_MAX),
-			"a" (UINT32_MAX):
-			"memory");
+	xsaves(&ectx->xs_area, UINT64_MAX);
 }
 
 void rstore_xsave_area(const struct ext_context *ectx)
 {
 	write_xcr(0, ectx->xcr0);
 	msr_write(MSR_IA32_XSS, ectx->xss);
-	asm volatile("xrstors %0"
-			: : "m" (ectx->xs_area),
-			"d" (UINT32_MAX),
-			"a" (UINT32_MAX):
-			"memory");
+	xrstors(&ectx->xs_area, UINT64_MAX);
 }
 
 /* TODO:

hypervisor/include/arch/x86/cpu.h

@@ -635,6 +635,25 @@ static inline uint64_t read_xcr(int32_t reg)
 	asm volatile ("xgetbv ": "=a"(xcrl), "=d"(xcrh) : "c" (reg));
 	return (((uint64_t)xcrh << 32U) | xcrl);
 }
+
+static inline void xsaves(struct xsave_area *region_addr, uint64_t mask)
+{
+	asm volatile("xsaves %0"
+			: : "m" (*(region_addr)),
+			"d" ((uint32_t)(mask >> 32U)),
+			"a" ((uint32_t)mask):
+			"memory");
+}
+
+static inline void xrstors(const struct xsave_area *region_addr, uint64_t mask)
+{
+	asm volatile("xrstors %0"
+			: : "m" (*(region_addr)),
+			"d" ((uint32_t)(mask >> 32U)),
+			"a" ((uint32_t)mask):
+			"memory");
+}
+
 /*
  * stac/clac pair is used to access guest's memory protected by SMAP,
  * following below flow: