Merge tag 'char-misc-4.13-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregk...

[karo-tx-linux.git] / arch / x86 / xen / enlighten_hvm.c

diff --git a/arch/x86/xen/enlighten_hvm.c b/arch/x86/xen/enlighten_hvm.c
index 87d791356ea9052f79f23e00f5d0024ff8cf0b7f..de503c225ae1f194b10c71b44528ad2a2a7a4c0d 100644 (file)
--- a/arch/x86/xen/enlighten_hvm.c
+++ b/arch/x86/xen/enlighten_hvm.c
@@ -12,6 +12,7 @@
 #include <asm/setup.h>
 #include <asm/hypervisor.h>
 #include <asm/e820/api.h>
+#include <asm/early_ioremap.h>
 
 #include <asm/xen/cpuid.h>
 #include <asm/xen/hypervisor.h>
@@ -21,38 +22,50 @@
 #include "mmu.h"
 #include "smp.h"
 
-void __ref xen_hvm_init_shared_info(void)
+static unsigned long shared_info_pfn;
+
+void xen_hvm_init_shared_info(void)
 {
        struct xen_add_to_physmap xatp;
-       u64 pa;
-
-       if (HYPERVISOR_shared_info == &xen_dummy_shared_info) {
-               /*
-                * Search for a free page starting at 4kB physical address.
-                * Low memory is preferred to avoid an EPT large page split up
-                * by the mapping.
-                * Starting below X86_RESERVE_LOW (usually 64kB) is fine as
-                * the BIOS used for HVM guests is well behaved and won't
-                * clobber memory other than the first 4kB.
-                */
-               for (pa = PAGE_SIZE;
-                    !e820__mapped_all(pa, pa + PAGE_SIZE, E820_TYPE_RAM) ||
-                    memblock_is_reserved(pa);
-                    pa += PAGE_SIZE)
-                       ;
-
-               memblock_reserve(pa, PAGE_SIZE);
-               HYPERVISOR_shared_info = __va(pa);
-       }
 
        xatp.domid = DOMID_SELF;
        xatp.idx = 0;
        xatp.space = XENMAPSPACE_shared_info;
-       xatp.gpfn = virt_to_pfn(HYPERVISOR_shared_info);
+       xatp.gpfn = shared_info_pfn;
        if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
                BUG();
 }
 
+static void __init reserve_shared_info(void)
+{
+       u64 pa;
+
+       /*
+        * Search for a free page starting at 4kB physical address.
+        * Low memory is preferred to avoid an EPT large page split up
+        * by the mapping.
+        * Starting below X86_RESERVE_LOW (usually 64kB) is fine as
+        * the BIOS used for HVM guests is well behaved and won't
+        * clobber memory other than the first 4kB.
+        */
+       for (pa = PAGE_SIZE;
+            !e820__mapped_all(pa, pa + PAGE_SIZE, E820_TYPE_RAM) ||
+            memblock_is_reserved(pa);
+            pa += PAGE_SIZE)
+               ;
+
+       shared_info_pfn = PHYS_PFN(pa);
+
+       memblock_reserve(pa, PAGE_SIZE);
+       HYPERVISOR_shared_info = early_memremap(pa, PAGE_SIZE);
+}
+
+static void __init xen_hvm_init_mem_mapping(void)
+{
+       early_memunmap(HYPERVISOR_shared_info, PAGE_SIZE);
+       HYPERVISOR_shared_info = __va(PFN_PHYS(shared_info_pfn));
+}
+
 static void __init init_hvm_pv_info(void)
 {
        int major, minor;
@@ -153,6 +166,7 @@ static void __init xen_hvm_guest_init(void)
 
        init_hvm_pv_info();
 
+       reserve_shared_info();
        xen_hvm_init_shared_info();
 
        /*
@@ -218,5 +232,6 @@ const struct hypervisor_x86 x86_hyper_xen_hvm = {
        .init_platform          = xen_hvm_guest_init,
        .pin_vcpu               = xen_pin_vcpu,
        .x2apic_available       = xen_x2apic_para_available,
+       .init_mem_mapping       = xen_hvm_init_mem_mapping,
 };
 EXPORT_SYMBOL(x86_hyper_xen_hvm);