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| author | Juergen Gross <jgross@suse.com> | 2017-11-02 12:19:21 +0300 |
|---|---|---|
| committer | Boris Ostrovsky <boris.ostrovsky@oracle.com> | 2017-11-06 23:50:17 +0300 |
| commit | 8dca4d96c7d8058e7c97daad9ae0a76569ea31e6 (patch) | |
| tree | 171e808f1a9c34a655325193addb4206e8f5d1ff /drivers/xen | |
| parent | 223c8f3349f9ce52847dfa266b32761ac223b9ac (diff) | |
| download | linux-8dca4d96c7d8058e7c97daad9ae0a76569ea31e6.tar.xz | |
xen: select grant interface version
Grant v2 will be needed in cases where a frame number in the grant
table can exceed 32 bits. For PV guests this is a host feature, while
for HVM guests this is a guest feature.
So select grant v2 in case frame numbers can be larger than 32 bits
and grant v1 else.
For testing purposes add a way to specify the grant interface version
via a boot parameter.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Diffstat (limited to 'drivers/xen')
| -rw-r--r-- | drivers/xen/grant-table.c | 35 |
1 files changed, 33 insertions, 2 deletions
diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c index 573e7fe9b147..fa152832e0e6 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -33,6 +33,7 @@ #define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt +#include <linux/bootmem.h> #include <linux/sched.h> #include <linux/mm.h> #include <linux/slab.h> @@ -43,6 +44,7 @@ #include <linux/hardirq.h> #include <linux/workqueue.h> #include <linux/ratelimit.h> +#include <linux/moduleparam.h> #include <xen/xen.h> #include <xen/interface/xen.h> @@ -52,6 +54,9 @@ #include <xen/hvc-console.h> #include <xen/swiotlb-xen.h> #include <xen/balloon.h> +#ifdef CONFIG_X86 +#include <asm/xen/cpuid.h> +#endif #include <asm/xen/hypercall.h> #include <asm/xen/interface.h> @@ -68,6 +73,8 @@ static int gnttab_free_count; static grant_ref_t gnttab_free_head; static DEFINE_SPINLOCK(gnttab_list_lock); struct grant_frames xen_auto_xlat_grant_frames; +static unsigned int xen_gnttab_version; +module_param_named(version, xen_gnttab_version, uint, 0); static union { struct grant_entry_v1 *v1; @@ -1177,12 +1184,36 @@ static const struct gnttab_ops gnttab_v2_ops = { .query_foreign_access = gnttab_query_foreign_access_v2, }; +static bool gnttab_need_v2(void) +{ +#ifdef CONFIG_X86 + uint32_t base, width; + + if (xen_pv_domain()) { + base = xen_cpuid_base(); + if (cpuid_eax(base) < 5) + return false; /* Information not available, use V1. */ + width = cpuid_ebx(base + 5) & + XEN_CPUID_MACHINE_ADDRESS_WIDTH_MASK; + return width > 32 + PAGE_SHIFT; + } +#endif + return !!(max_possible_pfn >> 32); +} + static void gnttab_request_version(void) { - int rc; + long rc; struct gnttab_set_version gsv; - gsv.version = 1; + if (gnttab_need_v2()) + gsv.version = 2; + else + gsv.version = 1; + + /* Boot parameter overrides automatic selection. */ + if (xen_gnttab_version >= 1 && xen_gnttab_version <= 2) + gsv.version = xen_gnttab_version; rc = HYPERVISOR_grant_table_op(GNTTABOP_set_version, &gsv, 1); if (rc == 0 && gsv.version == 2) |