Module Name: src
Committed By: bouyer
Date: Tue Apr 21 16:57:40 UTC 2020
Modified Files:
src/sys/arch/xen/xen [bouyer-xenpvh]: xengnt.c
Log Message:
It is possible to use grant_v2 with HVM guest; but the status table has
to be mapped using XENMEM_add_to_physmap.
To generate a diff of this commit:
cvs rdiff -u -r1.29.2.2 -r1.29.2.3 src/sys/arch/xen/xen/xengnt.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/xen/xen/xengnt.c
diff -u src/sys/arch/xen/xen/xengnt.c:1.29.2.2 src/sys/arch/xen/xen/xengnt.c:1.29.2.3
--- src/sys/arch/xen/xen/xengnt.c:1.29.2.2 Mon Apr 20 19:42:10 2020
+++ src/sys/arch/xen/xen/xengnt.c Tue Apr 21 16:57:40 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: xengnt.c,v 1.29.2.2 2020/04/20 19:42:10 bouyer Exp $ */
+/* $NetBSD: xengnt.c,v 1.29.2.3 2020/04/21 16:57:40 bouyer Exp $ */
/*
* Copyright (c) 2006 Manuel Bouyer.
@@ -26,7 +26,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: xengnt.c,v 1.29.2.2 2020/04/20 19:42:10 bouyer Exp $");
+__KERNEL_RCSID(0, "$NetBSD: xengnt.c,v 1.29.2.3 2020/04/21 16:57:40 bouyer Exp $");
#include <sys/types.h>
#include <sys/param.h>
@@ -44,16 +44,6 @@ __KERNEL_RCSID(0, "$NetBSD: xengnt.c,v 1
#include "opt_xen.h"
-/*
- * grant table v2 is not supported for HVM guests on 4.11 at last.
- * see xen/arch/x86/hvm/hypercall.c in Xen sources (missing
- * GNTTABOP_get_status_frames)
- */
-
-#ifdef XENPV
-#define USE_GRANT_V2
-#endif
-
/* #define XENDEBUG */
#ifdef XENDEBUG
#define DPRINTF(x) printf x
@@ -77,7 +67,6 @@ int last_gnt_entry;
#define XENGNT_NO_ENTRY 0xffffffff
/* VM address of the grant table */
-#ifdef USE_GRANT_V2
#define NR_GRANT_ENTRIES_PER_PAGE (PAGE_SIZE / sizeof(grant_entry_v2_t))
#define NR_GRANT_STATUS_PER_PAGE (PAGE_SIZE / sizeof(grant_status_t))
@@ -86,10 +75,6 @@ grant_entry_v2_t *grant_table;
int gnt_status_frames;
grant_status_t *grant_status;
-#else /* USE_GRANT_V2 */
-#define NR_GRANT_ENTRIES_PER_PAGE (PAGE_SIZE / sizeof(grant_entry_v1_t))
-grant_entry_v1_t *grant_table;
-#endif /* USE_GRANT_V2 */
kmutex_t grant_lock;
static grant_ref_t xengnt_get_entry(void);
@@ -118,13 +103,11 @@ xengnt_init(void)
gnt_nr_grant_frames = gnt_max_grant_frames;
-#ifdef USE_GRANT_V2
struct gnttab_set_version gntversion;
gntversion.version = 2;
rc = HYPERVISOR_grant_table_op(GNTTABOP_set_version, &gntversion, 1);
if (rc < 0 || gntversion.version != 2)
panic("GNTTABOP_set_version 2 failed %d", rc);
-#endif /* USE_GRANT_V2 */
nr_grant_entries =
gnt_max_grant_frames * NR_GRANT_ENTRIES_PER_PAGE;
@@ -139,14 +122,12 @@ xengnt_init(void)
for (i = 0; i <= nr_grant_entries; i++)
gnt_entries[i] = XENGNT_NO_ENTRY;
-#ifdef USE_GRANT_V2
gnt_status_frames =
round_page(nr_grant_entries * sizeof(grant_status_t)) / PAGE_SIZE;
grant_status = (void *)uvm_km_alloc(kernel_map,
gnt_status_frames * PAGE_SIZE, 0, UVM_KMF_VAONLY);
if (grant_status == NULL)
panic("xengnt_init() status no VM space");
-#endif /* USE_GRANT_V2 */
mutex_init(&grant_lock, MUTEX_DEFAULT, IPL_VM);
@@ -194,10 +175,8 @@ xengnt_suspend(void) {
/* Remove virtual => machine mapping for grant table */
pmap_kremove((vaddr_t)grant_table, gnt_nr_grant_frames * PAGE_SIZE);
-#ifdef USE_GRANT_V2
/* Remove virtual => machine mapping for status table */
pmap_kremove((vaddr_t)grant_status, gnt_status_frames * PAGE_SIZE);
-#endif
pmap_update(pmap_kernel());
mutex_exit(&grant_lock);
@@ -210,12 +189,8 @@ xengnt_suspend(void) {
static int
xengnt_map_status(void)
{
-#ifdef USE_GRANT_V2
- gnttab_get_status_frames_t getstatus;
uint64_t *pages;
size_t sz;
- int err;
-
KASSERT(mutex_owned(&grant_lock));
sz = gnt_status_frames * sizeof(*pages);
@@ -223,6 +198,10 @@ xengnt_map_status(void)
if (pages == NULL)
return ENOMEM;
+#ifdef XENPV
+ gnttab_get_status_frames_t getstatus;
+ int err;
+
getstatus.dom = DOMID_SELF;
getstatus.nr_frames = gnt_status_frames;
set_xen_guest_handle(getstatus.frame_list, pages);
@@ -240,7 +219,23 @@ xengnt_map_status(void)
kmem_free(pages, sz);
return ENOMEM;
}
+#else /* XENPV */
+ for (int i = 0; i < gnt_status_frames; i++) {
+ struct vm_page *pg;
+ struct xen_add_to_physmap xmap;
+
+ pg = uvm_pagealloc(NULL, 0, NULL, UVM_PGA_USERESERVE|UVM_PGA_ZERO);
+ pages[i] = atop(uvm_vm_page_to_phys(pg));
+
+ xmap.domid = DOMID_SELF;
+ xmap.space = XENMAPSPACE_grant_table;
+ xmap.idx = i | XENMAPIDX_grant_table_status;
+ xmap.gpfn = pages[i];
+ if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xmap) < 0)
+ panic("%s: Unable to add grant tables\n", __func__);
+ }
+#endif /* XENPV */
/*
* map between status_table addresses and the machine addresses of
* the status table frames
@@ -253,8 +248,6 @@ xengnt_map_status(void)
pmap_update(pmap_kernel());
kmem_free(pages, sz);
-
-#endif /* USE_GRANT_V2 */
return 0;
}
@@ -298,7 +291,7 @@ xengnt_more_entries(void)
xmap.gpfn = pages[gnt_nr_grant_frames];
if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xmap) < 0)
- panic("%s: Unable to register HYPERVISOR_shared_info\n", __func__);
+ panic("%s: Unable to add grant frames\n", __func__);
} else {
setup.dom = DOMID_SELF;
@@ -398,7 +391,6 @@ xengnt_free_entry(grant_ref_t entry)
mutex_exit(&grant_lock);
}
-#ifdef USE_GRANT_V2
int
xengnt_grant_access(domid_t dom, paddr_t ma, int ro, grant_ref_t *entryp)
{
@@ -451,67 +443,3 @@ xengnt_status(grant_ref_t entry)
{
return grant_status[entry] & (GTF_reading|GTF_writing);
}
-#else /* USE_GRANT_V2 */
-
-int
-xengnt_grant_access(domid_t dom, paddr_t ma, int ro, grant_ref_t *entryp)
-{
- mutex_enter(&grant_lock);
-
- *entryp = xengnt_get_entry();
- if (__predict_false(*entryp == XENGNT_NO_ENTRY)) {
- mutex_exit(&grant_lock);
- return ENOMEM;
- }
-
- grant_table[*entryp].frame = ma >> PAGE_SHIFT;
- grant_table[*entryp].domid = dom;
- /*
- * ensure that the above values reach global visibility
- * before permitting frame's access (done when we set flags)
- */
- xen_rmb();
- grant_table[*entryp].flags =
- GTF_permit_access | (ro ? GTF_readonly : 0);
- mutex_exit(&grant_lock);
- return 0;
-}
-
-
-static inline uint16_t
-xen_atomic_cmpxchg16(volatile uint16_t *ptr, uint16_t val, uint16_t newval)
-{
- unsigned long result;
-
- __asm volatile(__LOCK_PREFIX
- "cmpxchgw %w1,%2"
- :"=a" (result)
- :"q"(newval), "m" (*ptr), "0" (val)
- :"memory");
-
- return result;
-}
-
-void
-xengnt_revoke_access(grant_ref_t entry)
-{
-
- uint16_t flags, nflags;
-
- nflags = grant_table[entry].flags;
-
- do {
- if ((flags = nflags) & (GTF_reading|GTF_writing))
- panic("xengnt_revoke_access: still in use");
- nflags = xen_atomic_cmpxchg16(&grant_table[entry].flags,
- flags, 0);
- } while (nflags != flags);
- xengnt_free_entry(entry);
-}
-
-int
-xengnt_status(grant_ref_t entry)
-{
- return (grant_table[entry].flags & (GTF_reading|GTF_writing));
-}
-#endif /* USE_GRANT_V2 */
