xen: eliminate scalability issues from initrd handling

Size restrictions native kernels wouldn't have resulted from the initrd
getting mapped into the initial mapping. The kernel doesn't really need
the initrd to be mapped, so use infrastructure available in Xen to avoid
the mapping and hence the restriction.

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index be1cff572ccf97bc03ddcf3958eeb6b918b87ce1..f7e01fa1545f9dd30ad3f8ca9fd91cc13f293d37 100644 (file)
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1519,6 +1519,7 @@ static void __init xen_pvh_early_guest_init(void)
 asmlinkage __visible void __init xen_start_kernel(void)
 {
        struct physdev_set_iopl set_iopl;
+       unsigned long initrd_start = 0;
        int rc;
 
        if (!xen_start_info)
@@ -1665,10 +1666,16 @@ asmlinkage __visible void __init xen_start_kernel(void)
        new_cpu_data.x86_capability[0] = cpuid_edx(1);
 #endif
 
+       if (xen_start_info->mod_start) {
+           if (xen_start_info->flags & SIF_MOD_START_PFN)
+               initrd_start = PFN_PHYS(xen_start_info->mod_start);
+           else
+               initrd_start = __pa(xen_start_info->mod_start);
+       }
+
        /* Poke various useful things into boot_params */
        boot_params.hdr.type_of_loader = (9 << 4) | 0;
-       boot_params.hdr.ramdisk_image = xen_start_info->mod_start
-               ? __pa(xen_start_info->mod_start) : 0;
+       boot_params.hdr.ramdisk_image = initrd_start;
        boot_params.hdr.ramdisk_size = xen_start_info->mod_len;
        boot_params.hdr.cmd_line_ptr = __pa(xen_start_info->cmd_line);
 

diff --git a/arch/x86/xen/xen-head.S b/arch/x86/xen/xen-head.S
index 485b69585540dc4fd67eada10d3a4c028aa81394..46408e51c1dcec12601d9941a07da8b6bc673cc3 100644 (file)
--- a/arch/x86/xen/xen-head.S
+++ b/arch/x86/xen/xen-head.S
@@ -124,6 +124,7 @@ NEXT_HYPERCALL(arch_6)
        ELFNOTE(Xen, XEN_ELFNOTE_L1_MFN_VALID,
                .quad _PAGE_PRESENT; .quad _PAGE_PRESENT)
        ELFNOTE(Xen, XEN_ELFNOTE_SUSPEND_CANCEL, .long 1)
+       ELFNOTE(Xen, XEN_ELFNOTE_MOD_START_PFN,  .long 1)
        ELFNOTE(Xen, XEN_ELFNOTE_HV_START_LOW,   _ASM_PTR __HYPERVISOR_VIRT_START)
        ELFNOTE(Xen, XEN_ELFNOTE_PADDR_OFFSET,   _ASM_PTR 0)