From: Konrad Rzeszutek Wilk Date: Fri, 3 Jan 2014 15:20:18 +0000 (-0500) Subject: xen/pvh: Piggyback on PVHVM for grant driver (v4) X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=6926f6d6109714aab7b26df7099b12555e36676f;p=linux-beck.git 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 Acked-by: Stefano Stabellini --- diff --git a/arch/x86/xen/grant-table.c b/arch/x86/xen/grant-table.c index 3a5f55d51907..2d719799fd6a 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 +#include +#include +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 diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c index e41c79c986ea..073b4a19a8b0 100644 --- a/drivers/xen/gntdev.c +++ b/drivers/xen/gntdev.c @@ -846,7 +846,7 @@ static int __init gntdev_init(void) if (!xen_domain()) return -ENODEV; - use_ptemod = xen_pv_domain(); + use_ptemod = !xen_feature(XENFEAT_auto_translated_physmap); err = misc_register(&gntdev_miscdev); if (err != 0) { diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c index 44b75ccfbbff..1d5fbce4acb7 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -1108,7 +1108,7 @@ static int gnttab_map(unsigned int start_idx, unsigned int end_idx) unsigned int nr_gframes = end_idx + 1; int rc; - if (xen_hvm_domain()) { + if (xen_feature(XENFEAT_auto_translated_physmap)) { struct xen_add_to_physmap xatp; unsigned int i = end_idx; rc = 0; @@ -1184,7 +1184,7 @@ static void gnttab_request_version(void) int rc; struct gnttab_set_version gsv; - if (xen_hvm_domain()) + if (xen_feature(XENFEAT_auto_translated_physmap)) gsv.version = 1; else gsv.version = 2; @@ -1327,5 +1327,6 @@ static int __gnttab_init(void) return gnttab_init(); } - -core_initcall(__gnttab_init); +/* Starts after core_initcall so that xen_pvh_gnttab_setup can be called + * beforehand to initialize xen_auto_xlat_grant_frames. */ +core_initcall_sync(__gnttab_init);