Commit 4ca83dcf authored by Juergen Gross's avatar Juergen Gross

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 a5d5f328 ("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: default avatarJuergen Gross <jgross@suse.com>
Reviewed-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
Acked-by: default avatarIngo Molnar <mingo@kernel.org>
Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
parent 10231f69
...@@ -12,6 +12,7 @@ ...@@ -12,6 +12,7 @@
#include <asm/setup.h> #include <asm/setup.h>
#include <asm/hypervisor.h> #include <asm/hypervisor.h>
#include <asm/e820/api.h> #include <asm/e820/api.h>
#include <asm/early_ioremap.h>
#include <asm/xen/cpuid.h> #include <asm/xen/cpuid.h>
#include <asm/xen/hypervisor.h> #include <asm/xen/hypervisor.h>
...@@ -21,6 +22,8 @@ ...@@ -21,6 +22,8 @@
#include "mmu.h" #include "mmu.h"
#include "smp.h" #include "smp.h"
static unsigned long shared_info_pfn;
void xen_hvm_init_shared_info(void) void xen_hvm_init_shared_info(void)
{ {
struct xen_add_to_physmap xatp; struct xen_add_to_physmap xatp;
...@@ -28,7 +31,7 @@ void xen_hvm_init_shared_info(void) ...@@ -28,7 +31,7 @@ void xen_hvm_init_shared_info(void)
xatp.domid = DOMID_SELF; xatp.domid = DOMID_SELF;
xatp.idx = 0; xatp.idx = 0;
xatp.space = XENMAPSPACE_shared_info; 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)) if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
BUG(); BUG();
} }
...@@ -51,8 +54,16 @@ static void __init reserve_shared_info(void) ...@@ -51,8 +54,16 @@ static void __init reserve_shared_info(void)
pa += PAGE_SIZE) pa += PAGE_SIZE)
; ;
shared_info_pfn = PHYS_PFN(pa);
memblock_reserve(pa, PAGE_SIZE); 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) static void __init init_hvm_pv_info(void)
...@@ -221,5 +232,6 @@ const struct hypervisor_x86 x86_hyper_xen_hvm = { ...@@ -221,5 +232,6 @@ const struct hypervisor_x86 x86_hyper_xen_hvm = {
.init_platform = xen_hvm_guest_init, .init_platform = xen_hvm_guest_init,
.pin_vcpu = xen_pin_vcpu, .pin_vcpu = xen_pin_vcpu,
.x2apic_available = xen_x2apic_para_available, .x2apic_available = xen_x2apic_para_available,
.init_mem_mapping = xen_hvm_init_mem_mapping,
}; };
EXPORT_SYMBOL(x86_hyper_xen_hvm); EXPORT_SYMBOL(x86_hyper_xen_hvm);
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