Revert "hv: More changes to enable GPU passthru"

This reverts commit 8d50d40.

Author: JasonChenCJ

hypervisor/arch/x86/ept.c

@@ -489,7 +489,7 @@ int ept_mmap(struct vm *vm, uint64_t hpa,
 		 * to force snooping of PCIe devices if the page
 		 * is cachable
 		 */
-		if ((prot & IA32E_EPT_MT_MASK) != IA32E_EPT_UNCACHED && iommu_snoop)
+		if ((prot & IA32E_EPT_MT_MASK) != IA32E_EPT_UNCACHED)
 			prot |= IA32E_EPT_SNOOP_CTRL;
 		map_mem(&map_params, (void *)hpa,
 			(void *)gpa, size, prot);

hypervisor/arch/x86/vtd.c

@@ -152,8 +152,6 @@ struct iommu_domain {
 	uint64_t trans_table_ptr;
 };
 
-bool iommu_snoop = true; /* enable iommu snoop control */
-
 static struct list_head dmar_drhd_units;
 static uint32_t dmar_hdrh_unit_count;
 
@@ -421,13 +419,9 @@ static void dmar_register_hrhd(struct dmar_drhd_rt *dmar_uint)
 	 * How to guarantee it when EPT is used as second-level
 	 * translation paging structures?
 	 */
-
-	/* enable snoop control only if it is supported by all the VT-d engines */
-	if (!iommu_ecap_sc(dmar_uint->ecap)) {
+	if (iommu_ecap_sc(dmar_uint->ecap) == 0U)
 		dev_dbg(ACRN_DBG_IOMMU,
 			"dmar uint doesn't support snoop control!");
-		iommu_snoop = false;
-	}
 
 	dmar_uint->max_domain_id = iommu_cap_ndoms(dmar_uint->cap) - 1;
 
@@ -1015,6 +1009,7 @@ static int add_iommu_device(struct iommu_domain *domain, uint16_t segment,
 			ASSERT(false,
 				  "dmaru doesn't support trans passthrough");
 	} else {
+		/* TODO: add Device TLB support */
 		upper =
 			DMAR_SET_BITSLICE(upper, CTX_ENTRY_UPPER_AW,
 					  width_to_agaw(

hypervisor/boot/dmar_parse.c

@@ -270,6 +270,13 @@ handle_one_drhd(struct acpi_dmar_hardware_unit *acpi_drhd,
 
 		consumed = handle_dmar_devscope(dev_scope, cp, remaining);
 
+		if (((drhd->segment << 16) |
+		     (dev_scope->bus << 8) |
+		     dev_scope->devfun) == CONFIG_GPU_SBDF) {
+			ASSERT(dev_count == 1, "no dedicated iommu for gpu");
+			drhd->ignore = true;
+		}
+
 		if (consumed <= 0)
 			break;
 

hypervisor/bsp/sbl/sbl.c

@@ -33,7 +33,7 @@ static struct dmar_drhd drhd_info_array[] = {
 		/* Ignore the iommu for intel graphic device since GVT-g needs
 		 * vtd disabled for gpu
 		 */
-		.ignore = false,
+		.ignore = true,
 		.devices = default_drhd_unit_dev_scope0,
 	},
 	{

hypervisor/bsp/uefi/include/bsp/bsp_cfg.h

@@ -21,6 +21,7 @@
 #define	CONFIG_RAM_START	0x20000000
 #define	CONFIG_RAM_SIZE		0x02000000	/* 32M */
 #define	CONFIG_DMAR_PARSE_ENABLED	1
+#define	CONFIG_GPU_SBDF		0x00000010	/* 0000:00:02.0 */
 #define CONFIG_EFI_STUB       1
 #define CONFIG_UEFI_OS_LOADER_NAME  "\\EFI\\org.clearlinux\\bootloaderx64.efi"
 #define CONFIG_MTRR_ENABLED		1

hypervisor/include/arch/x86/vtd.h

@@ -206,8 +206,6 @@ struct dmar_info {
 
 extern struct dmar_info *get_dmar_info(void);
 
-extern bool iommu_snoop;
-
 struct iommu_domain;
 
 /* Assign a device specified by bus & devfun to a iommu domain */