diff options
Diffstat (limited to 'arch/x86/xen/enlighten_hvm.c')
| -rw-r--r-- | arch/x86/xen/enlighten_hvm.c | 31 |
1 files changed, 24 insertions, 7 deletions
diff --git a/arch/x86/xen/enlighten_hvm.c b/arch/x86/xen/enlighten_hvm.c index 13b5fa1a211c..87d791356ea9 100644 --- a/arch/x86/xen/enlighten_hvm.c +++ b/arch/x86/xen/enlighten_hvm.c @@ -1,5 +1,6 @@ #include <linux/cpu.h> #include <linux/kexec.h> +#include <linux/memblock.h> #include <xen/features.h> #include <xen/events.h> @@ -10,9 +11,11 @@ #include <asm/reboot.h> #include <asm/setup.h> #include <asm/hypervisor.h> +#include <asm/e820/api.h> #include <asm/xen/cpuid.h> #include <asm/xen/hypervisor.h> +#include <asm/xen/page.h> #include "xen-ops.h" #include "mmu.h" @@ -21,19 +24,33 @@ void __ref xen_hvm_init_shared_info(void) { struct xen_add_to_physmap xatp; - static struct shared_info *shared_info_page; + 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); + } - if (!shared_info_page) - shared_info_page = (struct shared_info *) - extend_brk(PAGE_SIZE, PAGE_SIZE); xatp.domid = DOMID_SELF; xatp.idx = 0; xatp.space = XENMAPSPACE_shared_info; - xatp.gpfn = __pa(shared_info_page) >> PAGE_SHIFT; + xatp.gpfn = virt_to_pfn(HYPERVISOR_shared_info); if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp)) BUG(); - - HYPERVISOR_shared_info = (struct shared_info *)shared_info_page; } static void __init init_hvm_pv_info(void) |