VMCI: Add support for virtual IOMMU

This patch adds support for virtual IOMMU to the vmci module.  We switch
to DMA consistent mappings for guest queuepair and doorbell pages that
are passed to the device.  We still allocate each page individually,
since there's no guarantee that we'll get a contiguous block of physical
for an entire queuepair (especially since we allow up to 128 MiB!).

Also made the split between guest and host in the kernelIf struct much
clearer.  Now it's obvious which fields are which.

Acked-by: George Zhang <georgezhang@vmware.com>
Acked-by: Aditya Sarwade <asarwade@vmware.com>
Signed-off-by: Andy King <acking@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 16 insertions, 6 deletions

diff --git a/drivers/misc/vmw_vmci/vmci_guest.c b/drivers/misc/vmw_vmci/vmci_guest.c
index 60c01999f489..b3a2b763ecf2 100644
--- a/drivers/misc/vmw_vmci/vmci_guest.c
+++ b/drivers/misc/vmw_vmci/vmci_guest.c
@@ -65,9 +65,11 @@ struct vmci_guest_device {
 
 	void *data_buffer;
 	void *notification_bitmap;
+	dma_addr_t notification_base;
 };
 
 /* vmci_dev singleton device and supporting data*/
+struct pci_dev *vmci_pdev;
 static struct vmci_guest_device *vmci_dev_g;
 static DEFINE_SPINLOCK(vmci_dev_spinlock);
 
@@ -528,7 +530,9 @@ static int vmci_guest_probe_device(struct pci_dev *pdev,
 	 * well.
 	 */
 	if (capabilities & VMCI_CAPS_NOTIFICATIONS) {
-		vmci_dev->notification_bitmap = vmalloc(PAGE_SIZE);
+		vmci_dev->notification_bitmap = dma_alloc_coherent(
+			&pdev->dev, PAGE_SIZE, &vmci_dev->notification_base,
+			GFP_KERNEL);
 		if (!vmci_dev->notification_bitmap) {
 			dev_warn(&pdev->dev,
 				 "Unable to allocate notification bitmap\n");
@@ -546,6 +550,7 @@ static int vmci_guest_probe_device(struct pci_dev *pdev,
 	/* Set up global device so that we can start sending datagrams */
 	spin_lock_irq(&vmci_dev_spinlock);
 	vmci_dev_g = vmci_dev;
+	vmci_pdev = pdev;
 	spin_unlock_irq(&vmci_dev_spinlock);
 
 	/*
@@ -553,9 +558,8 @@ static int vmci_guest_probe_device(struct pci_dev *pdev,
 	 * used.
 	 */
 	if (capabilities & VMCI_CAPS_NOTIFICATIONS) {
-		struct page *page =
-			vmalloc_to_page(vmci_dev->notification_bitmap);
-		unsigned long bitmap_ppn = page_to_pfn(page);
+		unsigned long bitmap_ppn =
+			vmci_dev->notification_base >> PAGE_SHIFT;
 		if (!vmci_dbell_register_notification_bitmap(bitmap_ppn)) {
 			dev_warn(&pdev->dev,
 				 "VMCI device unable to register notification bitmap with PPN 0x%x\n",
@@ -665,11 +669,14 @@ err_remove_bitmap:
 	if (vmci_dev->notification_bitmap) {
 		iowrite32(VMCI_CONTROL_RESET,
 			  vmci_dev->iobase + VMCI_CONTROL_ADDR);
-		vfree(vmci_dev->notification_bitmap);
+		dma_free_coherent(&pdev->dev, PAGE_SIZE,
+				  vmci_dev->notification_bitmap,
+				  vmci_dev->notification_base);
 	}
 
 err_remove_vmci_dev_g:
 	spin_lock_irq(&vmci_dev_spinlock);
+	vmci_pdev = NULL;
 	vmci_dev_g = NULL;
 	spin_unlock_irq(&vmci_dev_spinlock);
 
@@ -699,6 +706,7 @@ static void vmci_guest_remove_device(struct pci_dev *pdev)
 
 	spin_lock_irq(&vmci_dev_spinlock);
 	vmci_dev_g = NULL;
+	vmci_pdev = NULL;
 	spin_unlock_irq(&vmci_dev_spinlock);
 
 	dev_dbg(&pdev->dev, "Resetting vmci device\n");
@@ -727,7 +735,9 @@ static void vmci_guest_remove_device(struct pci_dev *pdev)
 		 * device, so we can safely free it here.
 		 */
 
-		vfree(vmci_dev->notification_bitmap);
+		dma_free_coherent(&pdev->dev, PAGE_SIZE,
+				  vmci_dev->notification_bitmap,
+				  vmci_dev->notification_base);
 	}
 
 	vfree(vmci_dev->data_buffer);