[xen staging] Revert "xen/arm: Alloc XenStore page for Dom0less DomUs from hypervisor"

[patchbot@xxxxxxx]

commit efa6e9f15ba943d154e8d7b29384581915b2aacd
Author:     Julien Grall <jgrall@xxxxxxxxxx>
AuthorDate: Wed Jun 19 12:48:09 2024 +0100
Commit:     Julien Grall <jgrall@xxxxxxxxxx>
CommitDate: Wed Jun 19 12:48:47 2024 +0100

    Revert "xen/arm: Alloc XenStore page for Dom0less DomUs from hypervisor"
    
    Michal reported that the gitlab CI is failing because of this series
    [1].
    
    This reverts commit 6f9d90ea943b5e0c5d11a71090c49bbfd79e97ea.
    
    Signed-off-by: Julien Grall <jgrall@xxxxxxxxxx>
---
 tools/helpers/init-dom0less.c | 58 ++++++++++++++++++++++++++++++++-----------
 xen/arch/arm/dom0less-build.c | 58 +------------------------------------------
 2 files changed, 45 insertions(+), 71 deletions(-)

diff --git a/tools/helpers/init-dom0less.c b/tools/helpers/init-dom0less.c
index 325527f040..fee93459c4 100644
--- a/tools/helpers/init-dom0less.c
+++ b/tools/helpers/init-dom0less.c
@@ -16,18 +16,30 @@
 
 #include "init-dom-json.h"
 
+#define XENSTORE_PFN_OFFSET 1
 #define STR_MAX_LENGTH 128
 
-static int get_xs_page(struct xc_interface_core *xch, libxl_dominfo *info,
-                       uint64_t *xenstore_pfn)
+static int alloc_xs_page(struct xc_interface_core *xch,
+                         libxl_dominfo *info,
+                         uint64_t *xenstore_pfn)
 {
     int rc;
+    const xen_pfn_t base = GUEST_MAGIC_BASE >> XC_PAGE_SHIFT;
+    xen_pfn_t p2m = (GUEST_MAGIC_BASE >> XC_PAGE_SHIFT) + XENSTORE_PFN_OFFSET;
 
-    rc = xc_hvm_param_get(xch, info->domid, HVM_PARAM_STORE_PFN, xenstore_pfn);
-    if (rc < 0) {
-        fprintf(stderr,"Failed to get HVM_PARAM_STORE_PFN\n");
-        return 1;
-    }
+    rc = xc_domain_setmaxmem(xch, info->domid,
+                             info->max_memkb + (XC_PAGE_SIZE/1024));
+    if (rc < 0)
+        return rc;
+
+    rc = xc_domain_populate_physmap_exact(xch, info->domid, 1, 0, 0, &p2m);
+    if (rc < 0)
+        return rc;
+
+    *xenstore_pfn = base + XENSTORE_PFN_OFFSET;
+    rc = xc_clear_domain_page(xch, info->domid, *xenstore_pfn);
+    if (rc < 0)
+        return rc;
 
     return 0;
 }
@@ -88,7 +100,6 @@ static bool do_xs_write_vm(struct xs_handle *xsh, 
xs_transaction_t t,
  */
 static int create_xenstore(struct xs_handle *xsh,
                            libxl_dominfo *info, libxl_uuid uuid,
-                           uint64_t xenstore_pfn,
                            evtchn_port_t xenstore_port)
 {
     domid_t domid;
@@ -134,7 +145,8 @@ static int create_xenstore(struct xs_handle *xsh,
     rc = snprintf(target_memkb_str, STR_MAX_LENGTH, "%"PRIu64, 
info->current_memkb);
     if (rc < 0 || rc >= STR_MAX_LENGTH)
         return rc;
-    rc = snprintf(ring_ref_str, STR_MAX_LENGTH, "%"PRIu64, xenstore_pfn);
+    rc = snprintf(ring_ref_str, STR_MAX_LENGTH, "%lld",
+                  (GUEST_MAGIC_BASE >> XC_PAGE_SHIFT) + XENSTORE_PFN_OFFSET);
     if (rc < 0 || rc >= STR_MAX_LENGTH)
         return rc;
     rc = snprintf(xenstore_port_str, STR_MAX_LENGTH, "%u", xenstore_port);
@@ -218,6 +230,7 @@ static int init_domain(struct xs_handle *xsh,
     libxl_uuid uuid;
     uint64_t xenstore_evtchn, xenstore_pfn;
     int rc;
+    struct xenstore_domain_interface *intf;
 
     printf("Init dom0less domain: %u\n", info->domid);
 
@@ -232,11 +245,20 @@ static int init_domain(struct xs_handle *xsh,
     if (!xenstore_evtchn)
         return 0;
 
-    /* Get xenstore page */
-    if (get_xs_page(xch, info, &xenstore_pfn) != 0) {
-        fprintf(stderr,"Error on getting xenstore page\n");
+    /* Alloc xenstore page */
+    if (alloc_xs_page(xch, info, &xenstore_pfn) != 0) {
+        printf("Error on alloc magic pages\n");
+        return 1;
+    }
+
+    intf = xenforeignmemory_map(xfh, info->domid, PROT_READ | PROT_WRITE, 1,
+                                &xenstore_pfn, NULL);
+    if (!intf) {
+        printf("Error mapping xenstore page\n");
         return 1;
     }
+    intf->connection = XENSTORE_RECONNECT;
+    xenforeignmemory_unmap(xfh, intf, 1);
 
     rc = xc_dom_gnttab_seed(xch, info->domid, true,
                             (xen_pfn_t)-1, xenstore_pfn, 0, 0);
@@ -250,11 +272,19 @@ static int init_domain(struct xs_handle *xsh,
     if (rc)
         err(1, "gen_stub_json_config");
 
-    rc = create_xenstore(xsh, info, uuid, xenstore_pfn, xenstore_evtchn);
+    /* Now everything is ready: set HVM_PARAM_STORE_PFN */
+    rc = xc_hvm_param_set(xch, info->domid, HVM_PARAM_STORE_PFN,
+                          xenstore_pfn);
+    if (rc < 0)
+        return rc;
+
+    rc = create_xenstore(xsh, info, uuid, xenstore_evtchn);
     if (rc)
         err(1, "writing to xenstore");
 
-    rc = xs_introduce_domain(xsh, info->domid, xenstore_pfn, xenstore_evtchn);
+    rc = xs_introduce_domain(xsh, info->domid,
+            (GUEST_MAGIC_BASE >> XC_PAGE_SHIFT) + XENSTORE_PFN_OFFSET,
+            xenstore_evtchn);
     if (!rc)
         err(1, "xs_introduce_domain");
     return 0;
diff --git a/xen/arch/arm/dom0less-build.c b/xen/arch/arm/dom0less-build.c
index ef2ba85ff4..f919d3acf9 100644
--- a/xen/arch/arm/dom0less-build.c
+++ b/xen/arch/arm/dom0less-build.c
@@ -1,6 +1,5 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 #include <xen/device_tree.h>
-#include <xen/domain_page.h>
 #include <xen/err.h>
 #include <xen/event.h>
 #include <xen/grant_table.h>
@@ -11,8 +10,6 @@
 #include <xen/sizes.h>
 #include <xen/vmap.h>
 
-#include <public/io/xs_wire.h>
-
 #include <asm/arm64/sve.h>
 #include <asm/dom0less-build.h>
 #include <asm/domain_build.h>
@@ -742,56 +739,6 @@ static int __init alloc_xenstore_evtchn(struct domain *d)
     return 0;
 }
 
-#define XENSTORE_PFN_OFFSET 1
-static int __init alloc_xenstore_page(struct domain *d)
-{
-    struct page_info *xenstore_pg;
-    struct xenstore_domain_interface *interface;
-    mfn_t mfn;
-    gfn_t gfn;
-    int rc;
-
-    if ( (UINT_MAX - d->max_pages) < 1 )
-    {
-        printk(XENLOG_ERR "%pd: Over-allocation for d->max_pages by 1 page.\n",
-               d);
-        return -EINVAL;
-    }
-    d->max_pages += 1;
-    xenstore_pg = alloc_domheap_page(d, MEMF_bits(32));
-    if ( xenstore_pg == NULL && is_64bit_domain(d) )
-        xenstore_pg = alloc_domheap_page(d, 0);
-    if ( xenstore_pg == NULL )
-        return -ENOMEM;
-
-    mfn = page_to_mfn(xenstore_pg);
-    if ( !mfn_x(mfn) )
-    {
-        free_domheap_page(xenstore_pg);
-        return -ENOMEM;
-    }
-
-    if ( !is_domain_direct_mapped(d) )
-        gfn = gaddr_to_gfn(GUEST_MAGIC_BASE +
-                           (XENSTORE_PFN_OFFSET << PAGE_SHIFT));
-    else
-        gfn = gaddr_to_gfn(mfn_to_maddr(mfn));
-
-    rc = guest_physmap_add_page(d, gfn, mfn, 0);
-    if ( rc )
-    {
-        free_domheap_page(xenstore_pg);
-        return rc;
-    }
-
-    d->arch.hvm.params[HVM_PARAM_STORE_PFN] = gfn_x(gfn);
-    interface = map_domain_page(mfn);
-    interface->connection = XENSTORE_RECONNECT;
-    unmap_domain_page(interface);
-
-    return 0;
-}
-
 static int __init construct_domU(struct domain *d,
                                  const struct dt_device_node *node)
 {
@@ -892,10 +839,7 @@ static int __init construct_domU(struct domain *d,
         rc = alloc_xenstore_evtchn(d);
         if ( rc < 0 )
             return rc;
-
-        rc = alloc_xenstore_page(d);
-        if ( rc < 0 )
-            return rc;
+        d->arch.hvm.params[HVM_PARAM_STORE_PFN] = ~0ULL;
     }
 
     return rc;
--
generated by git-patchbot for /home/xen/git/xen.git#staging