WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-devel

[Xen-devel] [PATCH 03/16] xen dom0: Set up basic IO permissions for dom0

To: Ingo Molnar <mingo@xxxxxxx>
Subject: [Xen-devel] [PATCH 03/16] xen dom0: Set up basic IO permissions for dom0.
From: Jeremy Fitzhardinge <jeremy@xxxxxxxx>
Date: Wed, 27 May 2009 00:15:25 -0700
Cc: Chris Wright <chrisw@xxxxxxxxxx>, Xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxx>, Juan Quintela <quintela@xxxxxxxxxx>, Ky Srinivasan <ksrinivasan@xxxxxxxxxx>, kurt.hackel@xxxxxxxxxx, the arch/x86 maintainers <x86@xxxxxxxxxx>, Linux Kernel Mailing List <linux-kernel@xxxxxxxxxxxxxxx>, Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>, Jens Axboe <jens.axboe@xxxxxxxxxx>, Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>, Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>, Greg KH <gregkh@xxxxxxx>
Delivery-date: Wed, 27 May 2009 00:19:52 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <1243408538-21100-1-git-send-email-jeremy@xxxxxxxx>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <1243408538-21100-1-git-send-email-jeremy@xxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
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.

[ Impact: set iopl for dom0 kernel; map ISA ]

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
Signed-off-by: Juan Quintela <quintela@xxxxxxxxxx>
---
 arch/x86/xen/enlighten.c |    8 ++++++++
 arch/x86/xen/mmu.c       |   24 ++++++++++++++++++++++++
 arch/x86/xen/setup.c     |    6 +++++-
 arch/x86/xen/xen-ops.h   |    1 +
 4 files changed, 38 insertions(+), 1 deletions(-)

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 0a1700a..50580fc 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1045,6 +1045,7 @@ asmlinkage void __init xen_start_kernel(void)
 
        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;
 
@@ -1054,6 +1055,13 @@ asmlinkage void __init xen_start_kernel(void)
        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/mmu.c b/arch/x86/xen/mmu.c
index 760e3a5..dc840ed 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -1615,6 +1615,7 @@ static void *m2v(phys_addr_t maddr)
        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;
@@ -1840,6 +1841,29 @@ static void xen_set_fixmap(unsigned idx, phys_addr_t 
phys, pgprot_t prot)
 #endif
 }
 
+__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();
+}
+
 __init void xen_post_allocator_init(void)
 {
        pv_mmu_ops.set_pte = xen_set_pte;
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index ad0047f..dc55171 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -51,6 +51,9 @@ char * __init xen_memory_setup(void)
         * 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 @@ void __init xen_arch_setup(void)
 
        pm_idle = xen_idle;
 
-       paravirt_disable_iospace();
+       if (!xen_initial_domain())
+               paravirt_disable_iospace();
 
        fiddle_vdso();
 }
diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
index 5c50a10..6ff6203 100644
--- a/arch/x86/xen/xen-ops.h
+++ b/arch/x86/xen/xen-ops.h
@@ -29,6 +29,7 @@ void xen_setup_machphys_mapping(void);
 pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn);
 void xen_ident_map_ISA(void);
 void xen_reserve_top(void);
+void xen_ident_map_ISA(void);
 
 void xen_post_allocator_init(void);
 
-- 
1.6.0.6


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel