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authorKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2014-01-03 10:20:18 -0500
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2014-01-06 10:44:21 -0500
commit6926f6d6109714aab7b26df7099b12555e36676f (patch)
tree48d0a61f2db6b3d75ff90f83d3726d975a0cce5b /arch/x86/xen
parentefaf30a3357872cf0fc7d555b1f9968ec71535d3 (diff)
xen/pvh: Piggyback on PVHVM for grant driver (v4)
In PVH the shared grant frame is the PFN and not MFN, hence its mapped via the same code path as HVM. The allocation of the grant frame is done differently - we do not use the early platform-pci driver and have an ioremap area - instead we use balloon memory and stitch all of the non-contingous pages in a virtualized area. That means when we call the hypervisor to replace the GMFN with a XENMAPSPACE_grant_table type, we need to lookup the old PFN for every iteration instead of assuming a flat contingous PFN allocation. Lastly, we only use v1 for grants. This is because PVHVM is not able to use v2 due to no XENMEM_add_to_physmap calls on the error status page (see commit 69e8f430e243d657c2053f097efebc2e2cd559f0 xen/granttable: Disable grant v2 for HVM domains.) Until that is implemented this workaround has to be in place. Also per suggestions by Stefano utilize the PVHVM paths as they share common functionality. v2 of this patch moves most of the PVH code out in the arch/x86/xen/grant-table driver and touches only minimally the generic driver. v3, v4: fixes us some of the code due to earlier patches. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Diffstat (limited to 'arch/x86/xen')
-rw-r--r--arch/x86/xen/grant-table.c62
1 files changed, 62 insertions, 0 deletions
diff --git a/arch/x86/xen/grant-table.c b/arch/x86/xen/grant-table.c
index 3a5f55d5190..2d719799fd6 100644
--- a/arch/x86/xen/grant-table.c
+++ b/arch/x86/xen/grant-table.c
@@ -125,3 +125,65 @@ void arch_gnttab_unmap(void *shared, unsigned long nr_gframes)
apply_to_page_range(&init_mm, (unsigned long)shared,
PAGE_SIZE * nr_gframes, unmap_pte_fn, NULL);
}
+#ifdef CONFIG_XEN_PVH
+#include <xen/balloon.h>
+#include <xen/events.h>
+#include <linux/slab.h>
+static int __init xlated_setup_gnttab_pages(void)
+{
+ struct page **pages;
+ xen_pfn_t *pfns;
+ int rc;
+ unsigned int i;
+ unsigned long nr_grant_frames = gnttab_max_grant_frames();
+
+ BUG_ON(nr_grant_frames == 0);
+ pages = kcalloc(nr_grant_frames, sizeof(pages[0]), GFP_KERNEL);
+ if (!pages)
+ return -ENOMEM;
+
+ pfns = kcalloc(nr_grant_frames, sizeof(pfns[0]), GFP_KERNEL);
+ if (!pfns) {
+ kfree(pages);
+ return -ENOMEM;
+ }
+ rc = alloc_xenballooned_pages(nr_grant_frames, pages, 0 /* lowmem */);
+ if (rc) {
+ pr_warn("%s Couldn't balloon alloc %ld pfns rc:%d\n", __func__,
+ nr_grant_frames, rc);
+ kfree(pages);
+ kfree(pfns);
+ return rc;
+ }
+ for (i = 0; i < nr_grant_frames; i++)
+ pfns[i] = page_to_pfn(pages[i]);
+
+ rc = arch_gnttab_map_shared(pfns, nr_grant_frames, nr_grant_frames,
+ &xen_auto_xlat_grant_frames.vaddr);
+
+ kfree(pages);
+ if (rc) {
+ pr_warn("%s Couldn't map %ld pfns rc:%d\n", __func__,
+ nr_grant_frames, rc);
+ free_xenballooned_pages(nr_grant_frames, pages);
+ kfree(pfns);
+ return rc;
+ }
+
+ xen_auto_xlat_grant_frames.pfn = pfns;
+ xen_auto_xlat_grant_frames.count = nr_grant_frames;
+
+ return 0;
+}
+
+static int __init xen_pvh_gnttab_setup(void)
+{
+ if (!xen_pvh_domain())
+ return -ENODEV;
+
+ return xlated_setup_gnttab_pages();
+}
+/* Call it _before_ __gnttab_init as we need to initialize the
+ * xen_auto_xlat_grant_frames first. */
+core_initcall(xen_pvh_gnttab_setup);
+#endif