diff --git a/xen/arch/x86/hvm/dom0_build.c b/xen/arch/x86/hvm/dom0_build.c
index a9384af14304..cbc365d678d2 100644
--- a/xen/arch/x86/hvm/dom0_build.c
+++ b/xen/arch/x86/hvm/dom0_build.c
@@ -644,9 +644,11 @@ static bool __init check_and_adjust_load_address(
 }
 
 static int __init pvh_load_kernel(
-    struct domain *d, struct boot_module *image, struct boot_module *initrd,
-    paddr_t *entry, paddr_t *start_info_addr)
+    struct boot_domain *bd, paddr_t *entry, paddr_t *start_info_addr)
 {
+    struct domain *d = bd->d;
+    struct boot_module *image = bd->kernel;
+    struct boot_module *initrd = bd->ramdisk;
     void *image_base = bootstrap_map_bm(image);
     void *image_start = image_base + image->headroom;
     unsigned long image_len = image->size;
@@ -1304,14 +1306,12 @@ static void __hwdom_init pvh_setup_mmcfg(struct domain *d)
 int __init dom0_construct_pvh(struct boot_domain *bd)
 {
     paddr_t entry, start_info;
-    struct boot_module *image = bd->kernel;
-    struct boot_module *initrd = bd->ramdisk;
     struct domain *d = bd->d;
     int rc;
 
     printk(XENLOG_INFO "*** Building a PVH Dom%d ***\n", d->domain_id);
 
-    if ( image == NULL )
+    if ( bd->kernel == NULL )
         panic("Missing kernel boot module for %pd construction\n", d);
 
     if ( is_hardware_domain(d) )
@@ -1351,7 +1351,7 @@ int __init dom0_construct_pvh(struct boot_domain *bd)
         return rc;
     }
 
-    rc = pvh_load_kernel(d, image, initrd, &entry, &start_info);
+    rc = pvh_load_kernel(bd, &entry, &start_info);
     if ( rc )
     {
         printk("Failed to load Dom0 kernel\n");
diff --git a/xen/arch/x86/include/asm/bootdomain.h b/xen/arch/x86/include/asm/bootdomain.h
index bcbf36b13f25..ffda1509a63f 100644
--- a/xen/arch/x86/include/asm/bootdomain.h
+++ b/xen/arch/x86/include/asm/bootdomain.h
@@ -14,6 +14,8 @@ struct boot_module;
 struct domain;
 
 struct boot_domain {
+    const char *cmdline;
+
     domid_t domid;
 
     struct boot_module *kernel;
diff --git a/xen/arch/x86/pv/dom0_build.c b/xen/arch/x86/pv/dom0_build.c
index e0709a1c1a7a..580f2703a154 100644
--- a/xen/arch/x86/pv/dom0_build.c
+++ b/xen/arch/x86/pv/dom0_build.c
@@ -972,8 +972,8 @@ static int __init dom0_construct(struct boot_domain *bd)
     }
 
     memset(si->cmd_line, 0, sizeof(si->cmd_line));
-    if ( image->cmdline_pa )
-        strlcpy((char *)si->cmd_line, __va(image->cmdline_pa), sizeof(si->cmd_line));
+    if ( bd->cmdline )
+        strlcpy((char *)si->cmd_line, bd->cmdline, sizeof(si->cmd_line));
 
 #ifdef CONFIG_VIDEO
     if ( !pv_shim && fill_console_start_info((void *)(si + 1)) )
diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
index a2178d5e8cc5..e6580382d247 100644
--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -965,10 +965,29 @@ static unsigned int __init copy_bios_e820(struct e820entry *map, unsigned int li
     return n;
 }
 
-static struct domain *__init create_dom0(struct boot_info *bi)
+static size_t __init domain_cmdline_size(
+    struct boot_info *bi, struct boot_domain *bd)
 {
-    static char __initdata cmdline[MAX_GUEST_CMDLINE];
+    size_t s = bi->kextra ? strlen(bi->kextra) : 0;
+
+    s += bd->kernel->cmdline_pa ? strlen(__va(bd->kernel->cmdline_pa)) : 0;
+
+    if ( s == 0 )
+        return s;
+
+    /*
+     * Certain parameters from the Xen command line may be added to the dom0
+     * command line. Add additional space for the possible cases along with one
+     * extra char to hold \0.
+     */
+    s += strlen(" noapic") + strlen(" acpi=") + sizeof(acpi_param) + 1;
+
+    return s;
+}
 
+static struct domain *__init create_dom0(struct boot_info *bi)
+{
+    char *cmdline = NULL;
     struct xen_domctl_createdomain dom0_cfg = {
         .flags = IS_ENABLED(CONFIG_TBOOT) ? XEN_DOMCTL_CDF_s3_integrity : 0,
         .max_evtchn_port = -1,
@@ -1008,19 +1027,30 @@ static struct domain *__init create_dom0(struct boot_info *bi)
         panic("Error creating d%uv0\n", bd->domid);
 
     /* Grab the DOM0 command line. */
-    if ( bd->kernel->cmdline_pa || bi->kextra )
+    if ( (bd->kernel->cmdline_pa &&
+          ((char *)__va(bd->kernel->cmdline_pa))[0]) ||
+         bi->kextra )
     {
+        size_t cmdline_size = domain_cmdline_size(bi, bd);
+
+        if ( cmdline_size == 0 )
+            goto skip_cmdline;
+
+        if ( !(cmdline = xzalloc_array(char, cmdline_size)) )
+            panic("Error allocating cmdline buffer for %pd\n", d);
+
         if ( bd->kernel->cmdline_pa )
-            safe_strcpy(cmdline,
-                        cmdline_cook(__va(bd->kernel->cmdline_pa), bi->loader));
+            strlcpy(cmdline,
+                    cmdline_cook(__va(bd->kernel->cmdline_pa),bi->loader),
+                    cmdline_size);
 
         if ( bi->kextra )
             /* kextra always includes exactly one leading space. */
-            safe_strcat(cmdline, bi->kextra);
+            strlcat(cmdline, bi->kextra, cmdline_size);
 
         /* Append any extra parameters. */
         if ( skip_ioapic_setup && !strstr(cmdline, "noapic") )
-            safe_strcat(cmdline, " noapic");
+            strlcat(cmdline, " noapic", cmdline_size);
 
         if ( (strlen(acpi_param) == 0) && acpi_disabled )
         {
@@ -1030,17 +1060,21 @@ static struct domain *__init create_dom0(struct boot_info *bi)
 
         if ( (strlen(acpi_param) != 0) && !strstr(cmdline, "acpi=") )
         {
-            safe_strcat(cmdline, " acpi=");
-            safe_strcat(cmdline, acpi_param);
+            strlcat(cmdline, " acpi=", cmdline_size);
+            strlcat(cmdline, acpi_param, cmdline_size);
         }
 
-        bd->kernel->cmdline_pa = __pa(cmdline);
+        bd->cmdline = cmdline;
     }
 
+ skip_cmdline:
     bd->d = d;
     if ( construct_dom0(bd) != 0 )
         panic("Could not construct domain 0\n");
 
+    if ( cmdline )
+        xfree(cmdline);
+
     return d;
 }
 
