From: Juan Quintela <quintela@xxxxxxxxxx>
Add the direct mapping area for ISA bus access, and enable IO space
access for the guest when running as dom0.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
Signed-off-by: Juan Quintela <quintela@xxxxxxxxxx>
---
arch/x86/xen/enlighten.c | 32 ++++++++++++++++++++++++++++++++
arch/x86/xen/setup.c | 6 +++++-
2 files changed, 37 insertions(+), 1 deletion(-)
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1437,6 +1437,7 @@
return __ka(m2p(maddr));
}
+/* Set the page permissions on an identity-mapped pages */
static void set_page_prot(void *addr, pgprot_t prot)
{
unsigned long pfn = __pa(addr) >> PAGE_SHIFT;
@@ -1492,6 +1493,29 @@
set_page_prot(pmd, PAGE_KERNEL_RO);
}
+static __init void xen_ident_map_ISA(void)
+{
+ unsigned long pa;
+
+ /*
+ * If we're dom0, then linear map the ISA machine addresses into
+ * the kernel's address space.
+ */
+ if (!xen_initial_domain())
+ return;
+
+ xen_raw_printk("Xen: setup ISA identity maps\n");
+
+ for (pa = ISA_START_ADDRESS; pa < ISA_END_ADDRESS; pa += PAGE_SIZE) {
+ pte_t pte = mfn_pte(PFN_DOWN(pa), PAGE_KERNEL_IO);
+
+ if (HYPERVISOR_update_va_mapping(PAGE_OFFSET + pa, pte, 0))
+ BUG();
+ }
+
+ xen_flush_tlb();
+}
+
#ifdef CONFIG_X86_64
static void convert_pfn_mfn(void *v)
{
@@ -1674,6 +1698,7 @@
xen_raw_console_write("mapping kernel into physical memory\n");
pgd = xen_setup_kernel_pagetable(pgd, xen_start_info->nr_pages);
+ xen_ident_map_ISA();
init_mm.pgd = pgd;
@@ -1683,6 +1708,13 @@
if (xen_feature(XENFEAT_supervisor_mode_kernel))
pv_info.kernel_rpl = 0;
+ if (xen_initial_domain()) {
+ struct physdev_set_iopl set_iopl;
+ set_iopl.iopl = 1;
+ if (HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl) == -1)
+ BUG();
+ }
+
/* set the limit of our address space */
xen_reserve_top();
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -51,6 +51,9 @@
* Even though this is normal, usable memory under Xen, reserve
* ISA memory anyway because too many things think they can poke
* about in there.
+ *
+ * In a dom0 kernel, this region is identity mapped with the
+ * hardware ISA area, so it really is out of bounds.
*/
e820_add_region(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS,
E820_RESERVED);
@@ -188,7 +191,8 @@
pm_idle = xen_idle;
- paravirt_disable_iospace();
+ if (!xen_initial_domain())
+ paravirt_disable_iospace();
fiddle_vdso();
}
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