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| author |   Juergen Gross <jgross@suse.com> | 2017-07-28 12:23:14 +0200 |
|---|---|---|
| committer | Juergen Gross <jgross@suse.com> | 2017-08-11 15:50:26 +0200 |
| commit | 4ca83dcf4e3bc0c98836dbb97553792ca7ea5429 (patch) | |
| tree | 58e2838e4e443252dbc6ef5a2837559b4c65f667 /arch | |
| parent | xen: split up xen_hvm_init_shared_info() (diff) | |
| download | linux-dev-4ca83dcf4e3bc0c98836dbb97553792ca7ea5429.tar.xz linux-dev-4ca83dcf4e3bc0c98836dbb97553792ca7ea5429.zip | |
xen: fix hvm guest with kaslr enabled
A Xen HVM guest running with KASLR enabled will die rather soon today
because the shared info page mapping is using va() too early. This was
introduced by commit a5d5f328b0e2baa5ee7c119fd66324eb79eeeb66 ("xen:
allocate page for shared info page from low memory").
In order to fix this use early_memremap() to get a temporary virtual
address for shared info until va() can be used safely.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Juergen Gross <jgross@suse.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/xen/enlighten_hvm.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/arch/x86/xen/enlighten_hvm.c b/arch/x86/xen/enlighten_hvm.c index d23531f5f17e..de503c225ae1 100644 --- 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> @@ -21,6 +22,8 @@ #include "mmu.h" #include "smp.h" +static unsigned long shared_info_pfn; + void xen_hvm_init_shared_info(void) { struct xen_add_to_physmap xatp; @@ -28,7 +31,7 @@ void xen_hvm_init_shared_info(void) 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(); } @@ -51,8 +54,16 @@ static void __init reserve_shared_info(void) pa += PAGE_SIZE) ; + shared_info_pfn = PHYS_PFN(pa); + memblock_reserve(pa, PAGE_SIZE); - HYPERVISOR_shared_info = __va(pa); + 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) @@ -221,5 +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); |