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 08/19] xen/dom0: use _PAGE_IOMAP in ioremap to do mac

To: Ingo Molnar <mingo@xxxxxxx>
Subject: [Xen-devel] [PATCH 08/19] xen/dom0: use _PAGE_IOMAP in ioremap to do machine mappings
From: Jeremy Fitzhardinge <jeremy@xxxxxxxx>
Date: Mon, 16 Feb 2009 15:46:01 -0800
Cc: Jeremy Fitzhardinge <jeremy@xxxxxxxx>, Xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxx>, Ian Campbell <Ian.Campbell@xxxxxxxxxx>, the arch/x86 maintainers <x86@xxxxxxxxxx>, Linux Kernel Mailing List <linux-kernel@xxxxxxxxxxxxxxx>, Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>, Yinghai Lu <yinghai@xxxxxxxxxx>
Delivery-date: Mon, 16 Feb 2009 16:00:43 -0800
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <630b678d3259163fc237f673b6f2a4a5fa76ac25.1234826723.git.jeremy.fitzhardinge@xxxxxxxxxx>
In-reply-to: <cover.1234826723.git.jeremy.fitzhardinge@xxxxxxxxxx>
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: <cover.1234826723.git.jeremy.fitzhardinge@xxxxxxxxxx> <cover.1234826723.git.jeremy.fitzhardinge@xxxxxxxxxx> <cover.1234826723.git.jeremy.fitzhardinge@xxxxxxxxxx> <edde7fdd064390d321bdafcfb993b28b4d2588b1.1234826723.git.jeremy.fitzhardinge@xxxxxxxxxx> <9fbd402b72d6c494f453ff86e071ac1b2658ece9.1234826723.git.jeremy.fitzhardinge@xxxxxxxxxx> <f47f399029ba9035a14ae381b6ae504a5c5bd445.1234826723.git.jeremy.fitzhardinge@xxxxxxxxxx> <f1402ed2345e1d654faa823afefa53fc4745e368.1234826723.git.jeremy.fitzhardinge@xxxxxxxxxx> <f0d2b3f946de1b3398c278c7a33069f670b78268.1234826723.git.jeremy.fitzhardinge@xxxxxxxxxx> <83b1377d81029933b769798dbe1ca134f6d365ae.1234826723.git.jeremy.fitzhardinge@xxxxxxxxxx> <630b678d3259163fc237f673b6f2a4a5fa76ac25.1234826723.git.jeremy.fitzhardinge@xxxxxxxxxx>
References: <cover.1234826723.git.jeremy.fitzhardinge@xxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
In a Xen domain, ioremap operates on machine addresses, not
pseudo-physical addresses.  We use _PAGE_IOMAP to determine whether a
mapping is intended for machine addresses.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
---
 arch/x86/include/asm/xen/page.h |    8 +---
 arch/x86/xen/enlighten.c        |    4 ++-
 arch/x86/xen/mmu.c              |   70 +++++++++++++++++++++++++++++++++++++-
 3 files changed, 73 insertions(+), 9 deletions(-)

diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h
index 4bd990e..20c3872 100644
--- a/arch/x86/include/asm/xen/page.h
+++ b/arch/x86/include/asm/xen/page.h
@@ -112,13 +112,9 @@ static inline xpaddr_t machine_to_phys(xmaddr_t machine)
  */
 static inline unsigned long mfn_to_local_pfn(unsigned long mfn)
 {
-       extern unsigned long max_mapnr;
        unsigned long pfn = mfn_to_pfn(mfn);
-       if ((pfn < max_mapnr)
-           && !xen_feature(XENFEAT_auto_translated_physmap)
-           && (get_phys_to_machine(pfn) != mfn))
-               return max_mapnr; /* force !pfn_valid() */
-       /* XXX fixme; not true with sparsemem */
+       if (get_phys_to_machine(pfn) != mfn)
+               return -1; /* force !pfn_valid() */
        return pfn;
 }
 
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 1b89d1c..c12a3c8 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -938,7 +938,9 @@ asmlinkage void __init xen_start_kernel(void)
 
        /* Prevent unwanted bits from being set in PTEs. */
        __supported_pte_mask &= ~_PAGE_GLOBAL;
-       if (!xen_initial_domain())
+       if (xen_initial_domain())
+               __supported_pte_mask |= _PAGE_IOMAP;
+       else
                __supported_pte_mask &= ~(_PAGE_PWT | _PAGE_PCD);
 
        /* Don't do the full vcpu_info placement stuff until we have a
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 36125ea..6aa6d55 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -336,6 +336,28 @@ static bool xen_page_pinned(void *ptr)
        return PagePinned(page);
 }
 
+static bool xen_iomap_pte(pte_t pte)
+{
+       return xen_initial_domain() && (pte_flags(pte) & _PAGE_IOMAP);
+}
+
+static void xen_set_iomap_pte(pte_t *ptep, pte_t pteval)
+{
+       struct multicall_space mcs;
+       struct mmu_update *u;
+
+       mcs = xen_mc_entry(sizeof(*u));
+       u = mcs.args;
+
+       /* ptep might be kmapped when using 32-bit HIGHPTE */
+       u->ptr = arbitrary_virt_to_machine(ptep).maddr;
+       u->val = pte_val_ma(pteval);
+
+       MULTI_mmu_update(mcs.mc, mcs.args, 1, NULL, DOMID_IO);
+
+       xen_mc_issue(PARAVIRT_LAZY_MMU);
+}
+
 static void xen_extend_mmu_update(const struct mmu_update *update)
 {
        struct multicall_space mcs;
@@ -416,6 +438,11 @@ void xen_set_pte_at(struct mm_struct *mm, unsigned long 
addr,
        if (mm == &init_mm)
                preempt_disable();
 
+       if (xen_iomap_pte(pteval)) {
+               xen_set_iomap_pte(ptep, pteval);
+               goto out;
+       }
+
        ADD_STATS(set_pte_at, 1);
 //     ADD_STATS(set_pte_at_pinned, xen_page_pinned(ptep));
        ADD_STATS(set_pte_at_current, mm == current->mm);
@@ -488,8 +515,25 @@ static pteval_t pte_pfn_to_mfn(pteval_t val)
        return val;
 }
 
+static pteval_t iomap_pte(pteval_t val)
+{
+       if (val & _PAGE_PRESENT) {
+               unsigned long pfn = (val & PTE_PFN_MASK) >> PAGE_SHIFT;
+               pteval_t flags = val & PTE_FLAGS_MASK;
+
+               /* We assume the pte frame number is a MFN, so
+                  just use it as-is. */
+               val = ((pteval_t)pfn << PAGE_SHIFT) | flags;
+       }
+
+       return val;
+}
+
 pteval_t xen_pte_val(pte_t pte)
 {
+       if (xen_initial_domain() && (pte.pte & _PAGE_IOMAP))
+               return pte.pte;
+
        return pte_mfn_to_pfn(pte.pte);
 }
 PV_CALLEE_SAVE_REGS_THUNK(xen_pte_val);
@@ -502,7 +546,11 @@ PV_CALLEE_SAVE_REGS_THUNK(xen_pgd_val);
 
 pte_t xen_make_pte(pteval_t pte)
 {
-       pte = pte_pfn_to_mfn(pte);
+       if (unlikely(xen_initial_domain() && (pte & _PAGE_IOMAP)))
+               pte = iomap_pte(pte);
+       else
+               pte = pte_pfn_to_mfn(pte);
+
        return native_make_pte(pte);
 }
 PV_CALLEE_SAVE_REGS_THUNK(xen_make_pte);
@@ -558,6 +606,11 @@ void xen_set_pud(pud_t *ptr, pud_t val)
 
 void xen_set_pte(pte_t *ptep, pte_t pte)
 {
+       if (xen_iomap_pte(pte)) {
+               xen_set_iomap_pte(ptep, pte);
+               return;
+       }
+
        ADD_STATS(pte_update, 1);
 //     ADD_STATS(pte_update_pinned, xen_page_pinned(ptep));
        ADD_STATS(pte_update_batched, paravirt_get_lazy_mode() == 
PARAVIRT_LAZY_MMU);
@@ -574,6 +627,11 @@ void xen_set_pte(pte_t *ptep, pte_t pte)
 #ifdef CONFIG_X86_PAE
 void xen_set_pte_atomic(pte_t *ptep, pte_t pte)
 {
+       if (xen_iomap_pte(pte)) {
+               xen_set_iomap_pte(ptep, pte);
+               return;
+       }
+
        set_64bit((u64 *)ptep, native_pte_val(pte));
 }
 
@@ -1770,12 +1828,20 @@ static void xen_set_fixmap(unsigned idx, unsigned long 
phys, pgprot_t prot)
 #ifdef CONFIG_X86_LOCAL_APIC
        case FIX_APIC_BASE:     /* maps dummy local APIC */
 #endif
+               /* All local page mappings */
                pte = pfn_pte(phys, prot);
                break;
 
-       default:
+       case FIX_PARAVIRT_BOOTMAP:
+               /* This is an MFN, but it isn't an IO mapping from the
+                  IO domain */
                pte = mfn_pte(phys, prot);
                break;
+
+       default:
+               /* By default, set_fixmap is used for hardware mappings */
+               pte = mfn_pte(phys, __pgprot(pgprot_val(prot) | _PAGE_IOMAP));
+               break;
        }
 
        __native_set_fixmap(idx, pte);
-- 
1.6.0.6


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

<Prev in Thread] Current Thread [Next in Thread>