xen: allow mapping ACPI data using a different physical address

When running as a Xen PV dom0 the system needs to map ACPI data of the
host using host physical addresses, while those addresses can conflict
with the guest physical addresses of the loaded linux kernel. The same
problem might apply in case a PV guest is configured to use the host
memory map.

This conflict can be solved by mapping the ACPI data to a different
guest physical address, but mapping the data via acpi_os_ioremap()
must still be possible using the host physical address, as this
address might be generated by AML when referencing some of the ACPI
data.

When configured to support running as a Xen PV domain, have an
implementation of acpi_os_ioremap() being aware of the possibility to
need above mentioned translation of a host physical address to the
guest physical address.

This modification requires to #include linux/acpi.h in some sources
which need to include asm/acpi.h directly.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>

diff --git a/arch/x86/include/asm/acpi.h b/arch/x86/include/asm/acpi.h
index 21bc53f5ed0c8108c9129558293e2a9ff944903c..5ab1a4598d00bc2d5534cda504c397d6d2f046a1 100644 (file)
--- a/arch/x86/include/asm/acpi.h
+++ b/arch/x86/include/asm/acpi.h
@@ -174,6 +174,14 @@ void acpi_generic_reduced_hw_init(void);
 void x86_default_set_root_pointer(u64 addr);
 u64 x86_default_get_root_pointer(void);
 
+#ifdef CONFIG_XEN_PV
+/* A Xen PV domain needs a special acpi_os_ioremap() handling. */
+extern void __iomem * (*acpi_os_ioremap)(acpi_physical_address phys,
+                                        acpi_size size);
+void __iomem *x86_acpi_os_ioremap(acpi_physical_address phys, acpi_size size);
+#define acpi_os_ioremap acpi_os_ioremap
+#endif
+
 #else /* !CONFIG_ACPI */
 
 #define acpi_lapic 0

diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 9f4618dcd7046555f79596cdad736375b9772a59..4efecac49863ec41e7d9bc6a2cf1a49265592f4a 100644 (file)
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -1778,3 +1778,14 @@ u64 x86_default_get_root_pointer(void)
 {
        return boot_params.acpi_rsdp_addr;
 }
+
+#ifdef CONFIG_XEN_PV
+void __iomem *x86_acpi_os_ioremap(acpi_physical_address phys, acpi_size size)
+{
+       return ioremap_cache(phys, size);
+}
+
+void __iomem * (*acpi_os_ioremap)(acpi_physical_address phys, acpi_size size) =
+       x86_acpi_os_ioremap;
+EXPORT_SYMBOL_GPL(acpi_os_ioremap);
+#endif

diff --git a/arch/x86/kernel/jailhouse.c b/arch/x86/kernel/jailhouse.c
index df337860612d844c668b5dcda8c308fa0c61480c..cd8ed1edbf9ee7637d6c557ee61e2799bc2f916d 100644 (file)
--- a/arch/x86/kernel/jailhouse.c
+++ b/arch/x86/kernel/jailhouse.c
@@ -12,6 +12,7 @@
 #include <linux/kernel.h>
 #include <linux/reboot.h>
 #include <linux/serial_8250.h>
+#include <linux/acpi.h>
 #include <asm/apic.h>
 #include <asm/io_apic.h>
 #include <asm/acpi.h>

diff --git a/arch/x86/kernel/mmconf-fam10h_64.c b/arch/x86/kernel/mmconf-fam10h_64.c
index c94dec6a18345a3a16574ca9944f402e4a9de410..1f54eedc3015e9bc6ac6c250bfe5b2c8c778ba0c 100644 (file)
--- a/arch/x86/kernel/mmconf-fam10h_64.c
+++ b/arch/x86/kernel/mmconf-fam10h_64.c
@@ -9,6 +9,7 @@
 #include <linux/pci.h>
 #include <linux/dmi.h>
 #include <linux/range.h>
+#include <linux/acpi.h>
 
 #include <asm/pci-direct.h>
 #include <linux/sort.h>

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 0c35207320cb4f6ded65d8ef64dbb24c63c1c84b..390e4fe7433ea3497e67175530af316110a1047a 100644 (file)
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -60,6 +60,7 @@
 #include <linux/stackprotector.h>
 #include <linux/cpuhotplug.h>
 #include <linux/mc146818rtc.h>
+#include <linux/acpi.h>
 
 #include <asm/acpi.h>
 #include <asm/cacheinfo.h>

diff --git a/arch/x86/kernel/x86_init.c b/arch/x86/kernel/x86_init.c
index 82b128d3f309702af4f7bbb3d3d2e3f541583adf..0a2bbd674a6d99b6301eec4082ac4b50dbbaaca4 100644 (file)
--- a/arch/x86/kernel/x86_init.c
+++ b/arch/x86/kernel/x86_init.c
@@ -8,6 +8,7 @@
 #include <linux/ioport.h>
 #include <linux/export.h>
 #include <linux/pci.h>
+#include <linux/acpi.h>
 
 #include <asm/acpi.h>
 #include <asm/bios_ebda.h>

diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index 2809bded30ea3d2b475ec54818f6c1703787ab39..b52d3e17e2c15287148c881a77b16585f0d25cf9 100644 (file)
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -70,6 +70,7 @@
 #include <linux/memblock.h>
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
+#include <linux/acpi.h>
 
 #include <asm/cache.h>
 #include <asm/setup.h>
@@ -834,6 +835,34 @@ void __init xen_do_remap_nonram(void)
        pr_info("Remapped %u non-RAM page(s)\n", remapped);
 }
 
+#ifdef CONFIG_ACPI
+/*
+ * Xen variant of acpi_os_ioremap() taking potentially remapped non-RAM
+ * regions into account.
+ * Any attempt to map an area crossing a remap boundary will produce a
+ * WARN() splat.
+ * phys is related to remap->maddr on input and will be rebased to remap->paddr.
+ */
+static void __iomem *xen_acpi_os_ioremap(acpi_physical_address phys,
+                                        acpi_size size)
+{
+       unsigned int i;
+       const struct nonram_remap *remap = xen_nonram_remap;
+
+       for (i = 0; i < nr_nonram_remap; i++) {
+               if (phys + size > remap->maddr &&
+                   phys < remap->maddr + remap->size) {
+                       WARN_ON(phys < remap->maddr ||
+                               phys + size > remap->maddr + remap->size);
+                       phys += remap->paddr - remap->maddr;
+                       break;
+               }
+       }
+
+       return x86_acpi_os_ioremap(phys, size);
+}
+#endif /* CONFIG_ACPI */
+
 /*
  * Add a new non-RAM remap entry.
  * In case of no free entry found, just crash the system.
@@ -848,6 +877,12 @@ void __init xen_add_remap_nonram(phys_addr_t maddr, phys_addr_t paddr,
                BUG();
        }
 
+#ifdef CONFIG_ACPI
+       /* Switch to the Xen acpi_os_ioremap() variant. */
+       if (nr_nonram_remap == 0)
+               acpi_os_ioremap = xen_acpi_os_ioremap;
+#endif
+
        xen_nonram_remap[nr_nonram_remap].maddr = maddr;
        xen_nonram_remap[nr_nonram_remap].paddr = paddr;
        xen_nonram_remap[nr_nonram_remap].size = size;

diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 2c79bb5a9cd095409b11bbd6a5cb8d7b0c20b7ee..1114e49937dac218e0bfe1625487b27df22f5367 100644 (file)
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -15,12 +15,12 @@
 #include <linux/cpuidle.h>
 #include <linux/cpufreq.h>
 #include <linux/memory_hotplug.h>
+#include <linux/acpi.h>
 
 #include <asm/elf.h>
 #include <asm/vdso.h>
 #include <asm/e820/api.h>
 #include <asm/setup.h>
-#include <asm/acpi.h>
 #include <asm/numa.h>
 #include <asm/idtentry.h>
 #include <asm/xen/hypervisor.h>