[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[PATCH v3 3/4] tools/init-dom0less: Avoid hardcoding GUEST_MAGIC_BASE


  • To: <xen-devel@xxxxxxxxxxxxxxxxxxxx>
  • From: Henry Wang <xin.wang2@xxxxxxx>
  • Date: Fri, 17 May 2024 11:21:55 +0800
  • Arc-authentication-results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 165.204.84.17) smtp.rcpttodomain=lists.xenproject.org smtp.mailfrom=amd.com; dmarc=pass (p=quarantine sp=quarantine pct=100) action=none header.from=amd.com; dkim=none (message not signed); arc=none (0)
  • Arc-message-signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=GyKN4QF9fVjSu+AyjNRAOue0Obnrq0vCp9OkHGHQS+8=; b=Ug61W5mJiOquEseiazbkFBTgKoFK+ldvDyyduTys/YrB2fyr7lE6071VIb+AC/qvWz7WFQWfhhtJyNQtbZP5iRe/leSUyGTZcr2IPcktTMFl14NOqJyAh1+N78ONe102cVjBOSemqx71tYwE8dRqbKHRozqr9L8OV3w54YCro69/xoXx8Jk8+48h1ZgsOEAHoJTEePvhPVRDt69+UUE5QQSyH/Xb+l4ihFhQil+REdOL/hG8b/rgemRighaHDXbmtefLkoxg3onSu4x4XRoykuQXGO+sssHlJfKldXzlhDLqqCapS74Y7nGcoSbKrtHJ8WneiCWyqP6ijzAsh/NlcA==
  • Arc-seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=Z1XYILrUxe22f+CO8p9a/Uy7Poo7DKsvyV4yI6p+LfGwfkcvdTz629vvLFTxr1DFF6TiKcTFOTJZtxCf6oyyB46z2sYsALR2xh8KbP1WeuPHzexdedS1dgZmMx9pYKGp96/q5Wq11teXco0VYDJ5m+F2pk7zqqx4nS7S2I6PhKZfQlxjqiFYXTyJDeG8n72xivvPXwvSjYOr0blm6B2fTtisdDOyawr918RW85ortydi/yLheM1Rhnmzz+B3L50shDv93LM0CVU2zatFp7z0RdtQOxA0ROyrinu1cz7XavlGlTOLpAPGF9FXUsfcHrD6NKqDeOp0LipiZY/1snYP9A==
  • Cc: Henry Wang <xin.wang2@xxxxxxx>, Anthony PERARD <anthony@xxxxxxxxxxxxxx>, Alec Kwapis <alec.kwapis@xxxxxxxxxxxxx>
  • Delivery-date: Fri, 17 May 2024 03:24:13 +0000
  • List-id: Xen developer discussion <xen-devel.lists.xenproject.org>

Currently the GUEST_MAGIC_BASE in the init-dom0less application is
hardcoded, which will lead to failures for 1:1 direct-mapped Dom0less
DomUs.

Since the guest magic region allocation from init-dom0less is for
XenStore, and the XenStore page is now allocated from the hypervisor,
instead of hardcoding the guest magic pages region, use
xc_hvm_param_get() to get the XenStore page PFN. Rename alloc_xs_page()
to get_xs_page() to reflect the changes.

With this change, some existing code is not needed anymore, including:
(1) The definition of the XenStore page offset.
(2) Call to xc_domain_setmaxmem() and xc_clear_domain_page() as we
    don't need to set the max mem and clear the page anymore.
(3) Foreign mapping of the XenStore page, setting of XenStore interface
    status and HVM_PARAM_STORE_PFN from init-dom0less, as they are set
    by the hypervisor.

Take the opportunity to do some coding style improvements when possible.

Reported-by: Alec Kwapis <alec.kwapis@xxxxxxxxxxxxx>
Signed-off-by: Henry Wang <xin.wang2@xxxxxxx>
---
v3:
- Only get the XenStore page.
- Drop the unneeded code.
v2:
- Update HVMOP keys name.
---
 tools/helpers/init-dom0less.c | 58 +++++++++--------------------------
 1 file changed, 14 insertions(+), 44 deletions(-)

diff --git a/tools/helpers/init-dom0less.c b/tools/helpers/init-dom0less.c
index fee93459c4..2b51965fa7 100644
--- a/tools/helpers/init-dom0less.c
+++ b/tools/helpers/init-dom0less.c
@@ -16,30 +16,18 @@
 
 #include "init-dom-json.h"
 
-#define XENSTORE_PFN_OFFSET 1
 #define STR_MAX_LENGTH 128
 
-static int alloc_xs_page(struct xc_interface_core *xch,
-                         libxl_dominfo *info,
-                         uint64_t *xenstore_pfn)
+static int get_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_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;
+    rc = xc_hvm_param_get(xch, info->domid, HVM_PARAM_STORE_PFN, xenstore_pfn);
+    if (rc < 0) {
+        printf("Failed to get HVM_PARAM_STORE_PFN\n");
+        return 1;
+    }
 
     return 0;
 }
@@ -100,6 +88,7 @@ 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;
@@ -145,8 +134,7 @@ 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, "%lld",
-                  (GUEST_MAGIC_BASE >> XC_PAGE_SHIFT) + XENSTORE_PFN_OFFSET);
+    rc = snprintf(ring_ref_str, STR_MAX_LENGTH, "%"PRIu64, xenstore_pfn);
     if (rc < 0 || rc >= STR_MAX_LENGTH)
         return rc;
     rc = snprintf(xenstore_port_str, STR_MAX_LENGTH, "%u", xenstore_port);
@@ -230,7 +218,6 @@ 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);
 
@@ -245,20 +232,11 @@ static int init_domain(struct xs_handle *xsh,
     if (!xenstore_evtchn)
         return 0;
 
-    /* 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");
+    /* Get xenstore page */
+    if (get_xs_page(xch, info, &xenstore_pfn) != 0) {
+        printf("Error on getting 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);
@@ -272,19 +250,11 @@ static int init_domain(struct xs_handle *xsh,
     if (rc)
         err(1, "gen_stub_json_config");
 
-    /* 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);
+    rc = create_xenstore(xsh, info, uuid, xenstore_pfn, xenstore_evtchn);
     if (rc)
         err(1, "writing to xenstore");
 
-    rc = xs_introduce_domain(xsh, info->domid,
-            (GUEST_MAGIC_BASE >> XC_PAGE_SHIFT) + XENSTORE_PFN_OFFSET,
-            xenstore_evtchn);
+    rc = xs_introduce_domain(xsh, info->domid, xenstore_pfn, xenstore_evtchn);
     if (!rc)
         err(1, "xs_introduce_domain");
     return 0;
-- 
2.34.1




 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.