HV: move bar emulation initialization code to pci_pt.c

Create the init_vdev_pt() function to host bar emulation initialization code

Add design philosophy for bar emulation

Move common functions to pci.h as they are generic and can be used by other
files.

Rename is_valid_bar to is_bar_supported and keep it as a private local function
in pci_pt.c

Tracked-On: #3056
Signed-off-by: dongshen <dongsheng.x.zhang@intel.com>
Reviewed-by: Eddie Dong <eddie.dong@intel.com>

Author: donsheng

hypervisor/dm/vpci/pci_pt.c

@@ -261,3 +261,74 @@ int32_t vdev_pt_cfgwrite(struct pci_vdev *vdev, uint32_t offset,
 
 	return ret;
 }
+
+/**
+ * For bar emulation, currently only MMIO is supported and bar size cannot be greater than 4GB
+ * @pre bar != NULL
+ */
+static inline bool is_bar_supported(const struct pci_bar *bar)
+{
+	return (is_mmio_bar(bar) && is_valid_bar_size(bar));
+}
+
+/**
+ * PCI base address register (bar) virtualization:
+ *
+ * Virtualize the PCI bars (up to 6 bars at byte offset 0x10~0x24 for type 0 PCI device,
+ * 2 bars at byte offset 0x10-0x14 for type 1 PCI device) of the PCI configuration space
+ * header.
+ *
+ * pbar: bar for the physical PCI device (pci_pdev), the value of pbar (hpa) is assigned
+ * by platform firmware during boot. It is assumed a valid hpa is always assigned to a
+ * mmio pbar, hypervisor shall not change the value of a pbar.
+ *
+ * vbar: for each pci_pdev, it has a virtual PCI device (pci_vdev) counterpart. pci_vdev
+ * virtualizes all the bars (called vbars). a vbar can be initialized by hypervisor by
+ * assigning a gpa to it; if vbar has a value of 0 (unassigned), guest may assign
+ * and program a gpa to it. The guest only sees the vbars, it will not see and can
+ * never change the pbars.
+ *
+ * Hypervisor traps guest changes to the mmio vbar (gpa) to establish ept mapping
+ * between vbar(gpa) and pbar(hpa). pbar should always align on 4K boundary.
+ *
+ * @pre vdev != NULL
+ * @pre vdev->vpci != NULL
+ * @pre vdev->vpci->vm != NULL
+ * @pre vdev->pdev != NULL
+ */
+void init_vdev_pt(struct pci_vdev *vdev)
+{
+	uint32_t idx;
+	struct pci_bar *pbar, *vbar;
+	uint16_t pci_command;
+
+	if (is_prelaunched_vm(vdev->vpci->vm)) {
+		for (idx = 0U; idx < (uint32_t)PCI_BAR_COUNT; idx++) {
+			pbar = &vdev->pdev->bar[idx];
+			vbar = &vdev->bar[idx];
+
+			if (is_bar_supported(pbar)) {
+				/**
+				 * If vbar->base is 0 (unassigned), Linux kernel will reprogram the vbar on
+				 * its bar size boundary, so in order to ensure the vbar allocated by guest
+				 * is 4k aligned, set its size to be 4K aligned.
+				 */
+				vbar->size = round_page_up(pbar->size);
+
+				/**
+				 * Only 32-bit bar is supported for now so both PCIBAR_MEM32 and PCIBAR_MEM64
+				 * are reported to guest as PCIBAR_MEM32
+				 */
+				vbar->type = PCIBAR_MEM32;
+			} else {
+				vbar->size = 0UL;
+				vbar->type = PCIBAR_NONE;
+			}
+		}
+
+		pci_command = (uint16_t)pci_pdev_read_cfg(vdev->pdev->bdf, PCIR_COMMAND, 2U);
+		/* Disable INTX */
+		pci_command |= 0x400U;
+		pci_pdev_write_cfg(vdev->pdev->bdf, PCIR_COMMAND, 2U, pci_command);
+	}
+}

hypervisor/dm/vpci/vpci.c

@@ -268,31 +268,6 @@ static inline bool is_hostbridge(const struct pci_vdev *vdev)
 	return (vdev->vbdf.value == 0U);
 }
 
-/**
- * @pre bar != NULL
- */
-static inline bool is_valid_bar_type(const struct pci_bar *bar)
-{
-	return (bar->type == PCIBAR_MEM32) || (bar->type == PCIBAR_MEM64);
-}
-
-/**
- * @pre bar != NULL
- */
-static inline bool is_valid_bar_size(const struct pci_bar *bar)
-{
-	return (bar->size > 0UL) && (bar->size <= 0xffffffffU);
-}
-
-/**
- * Only MMIO is supported and bar size cannot be greater than 4GB
- * @pre bar != NULL
- */
-static inline bool is_valid_bar(const struct pci_bar *bar)
-{
-	return (is_valid_bar_type(bar) && is_valid_bar_size(bar));
-}
-
 /**
  * @pre vdev != NULL
  * @pre vdev->vpci != NULL
@@ -341,35 +316,12 @@ static void remove_vdev_pt_iommu_domain(const struct pci_vdev *vdev)
 static void partition_mode_pdev_init(struct pci_vdev *vdev, union pci_bdf pbdf)
 {
 	struct pci_pdev *pdev;
-	uint32_t idx;
-	struct pci_bar *pbar, *vbar;
-	uint16_t pci_command;
 
 	pdev = find_pci_pdev(pbdf);
 	ASSERT(pdev != NULL, "pdev is NULL");
 
 	vdev->pdev = pdev;
 
-	/* Sanity checking for vbar */
-	for (idx = 0U; idx < (uint32_t)PCI_BAR_COUNT; idx++) {
-		pbar = &vdev->pdev->bar[idx];
-		vbar = &vdev->bar[idx];
-
-		if (is_valid_bar(pbar)) {
-			vbar->size = (pbar->size < 0x1000U) ? 0x1000U : pbar->size;
-			vbar->type = PCIBAR_MEM32;
-		} else {
-			/* Mark this vbar as invalid */
-			vbar->size = 0UL;
-			vbar->type = PCIBAR_NONE;
-		}
-	}
-
-	pci_command = (uint16_t)pci_pdev_read_cfg(vdev->pdev->bdf, PCIR_COMMAND, 2U);
-	/* Disable INTX */
-	pci_command |= 0x400U;
-	pci_pdev_write_cfg(vdev->pdev->bdf, PCIR_COMMAND, 2U, pci_command);
-
 	assign_vdev_pt_iommu_domain(vdev);
 }
 
@@ -402,6 +354,8 @@ int32_t partition_mode_vpci_init(struct acrn_vm *vm)
 		} else {
 			partition_mode_pdev_init(vdev, ptdev_config->pbdf);
 
+			init_vdev_pt(vdev);
+
 			vmsi_init(vdev);
 
 			vmsix_init(vdev);
@@ -560,7 +514,6 @@ static void init_vdev_for_pdev(struct pci_pdev *pdev, const void *vm)
 	}
 }
 
-
 /**
  * @pre vm != NULL
  * @pre is_sos_vm(vm) == true

hypervisor/dm/vpci/vpci_priv.h

@@ -80,6 +80,7 @@ int32_t vhostbridge_cfgread(const struct pci_vdev *vdev, uint32_t offset, uint32
 int32_t vhostbridge_cfgwrite(struct pci_vdev *vdev, uint32_t offset, uint32_t bytes, uint32_t val);
 void vhostbridge_deinit(__unused const struct pci_vdev *vdev);
 
+void init_vdev_pt(struct pci_vdev *vdev);
 int32_t vdev_pt_cfgread(const struct pci_vdev *vdev, uint32_t offset, uint32_t bytes, uint32_t *val);
 int32_t vdev_pt_cfgwrite(struct pci_vdev *vdev, uint32_t offset, uint32_t bytes, uint32_t val);
 

hypervisor/include/hw/pci.h

@@ -220,14 +220,31 @@ static inline uint8_t pci_devfn(uint16_t bdf)
 	return (uint8_t)(bdf & 0xFFU);
 }
 
-/*
- * @pre a != NULL && b != NULL
+/**
+ * @pre a != NULL
+ * @pre b != NULL
  */
 static inline bool bdf_is_equal(const union pci_bdf *a, const union pci_bdf *b)
 {
 	return (a->value == b->value);
 }
 
+/**
+ * @pre bar != NULL
+ */
+static inline bool is_mmio_bar(const struct pci_bar *bar)
+{
+	return (bar->type == PCIBAR_MEM32) || (bar->type == PCIBAR_MEM64);
+}
+
+/**
+ * @pre bar != NULL
+ */
+static inline bool is_valid_bar_size(const struct pci_bar *bar)
+{
+	return (bar->size > 0UL) && (bar->size <= 0xffffffffU);
+}
+
 uint32_t pci_pdev_read_cfg(union pci_bdf bdf, uint32_t offset, uint32_t bytes);
 void pci_pdev_write_cfg(union pci_bdf bdf, uint32_t offset, uint32_t bytes, uint32_t val);
 void enable_disable_pci_intx(union pci_bdf bdf, bool enable);