hv: Replace dynamic memory allocation for MSR bitmap

Replace pointer with static memory for msr_bitmap
inside structure vm_arch.

Tracked-On: #861
Signed-off-by: Mingqiang Chi <mingqiang.chi@intel.com>
Reviewed-by: Anthony Xu <anthony.xu@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>

Author: mingqiangchi

hypervisor/arch/x86/guest/vm.c

@@ -292,9 +292,6 @@ int shutdown_vm(struct vm *vm)
 	/* Free EPT allocated resources assigned to VM */
 	destroy_ept(vm);
 
-	/* Free MSR bitmap */
-	free(vm->arch_vm.msr_bitmap);
-
 	/* TODO: De-initialize I/O Emulation */
 	free_io_emulation_resource(vm);
 

hypervisor/arch/x86/guest/vmsr.c

@@ -55,20 +55,14 @@ void init_msr_emulation(struct vcpu *vcpu)
 {
 	uint32_t i;
 	uint32_t msrs_count =  ARRAY_SIZE(emulated_msrs);
-	void *msr_bitmap;
+	uint8_t *msr_bitmap;
 	uint64_t value64;
 
 	ASSERT(msrs_count == IDX_MAX_MSR,
 		"MSR ID should be matched with emulated_msrs");
 
 	/*msr bitmap, just allocated/init once, and used for all vm's vcpu*/
 	if (is_vcpu_bsp(vcpu)) {
-
-		/* Allocate and initialize memory for MSR bitmap region*/
-		vcpu->vm->arch_vm.msr_bitmap = alloc_page();
-		ASSERT(vcpu->vm->arch_vm.msr_bitmap != NULL, "");
-		(void)memset(vcpu->vm->arch_vm.msr_bitmap, 0x0U, CPU_PAGE_SIZE);
-
 		msr_bitmap = vcpu->vm->arch_vm.msr_bitmap;
 
 		for (i = 0U; i < msrs_count; i++) {

hypervisor/include/arch/x86/guest/vm.h

@@ -88,6 +88,8 @@ enum vm_state {
 struct vm_arch {
 	/* I/O bitmaps A and B for this VM, MUST be 4-Kbyte aligned */
 	uint8_t io_bitmap[CPU_PAGE_SIZE*2];
+	/* MSR bitmap region for this VM, MUST be 4-Kbyte aligned */
+	uint8_t msr_bitmap[CPU_PAGE_SIZE];
 
 	uint64_t guest_init_pml4;/* Guest init pml4 */
 	/* EPT hierarchy for Normal World */
@@ -99,7 +101,6 @@ struct vm_arch {
 	void *sworld_eptp;
 	void *m2p;		/* machine address to guest physical address */
 	void *tmp_pg_array;	/* Page array for tmp guest paging struct */
-	void *msr_bitmap;	/* MSR bitmap page base address for this VM */
 	struct acrn_vioapic vioapic;	/* Virtual IOAPIC base address */
 	struct acrn_vpic vpic;      /* Virtual PIC */
 	/**