xen: allow mapping ACPI data using a different physical address

commit 9221222c717dbddac1e3c49906525475d87a3a44 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/include/asm/acpi.h b/arch/x86/include/asm/acpi.h
index f896eed4516c7e3c131751ab5865aa70cfa2d645..529c36a98d9ea07306be4958437a2853a717c793 100644 (file)
--- a/arch/x86/include/asm/acpi.h
+++ b/arch/x86/include/asm/acpi.h
@@ -165,6 +165,14 @@ 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 c55c0ef47a187eb961616ea6af6eac8e246b1fe0..49c39f5dc1c992e4102231aae45ea785b3e1a5a3 100644 (file)
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -1901,3 +1901,14 @@ 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 578d16fc040fa1eadf31344b81877c1ed343b2cf..5481c7c5db301bf9aa4d4958a412d2b8c2511c98 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 2a187c0cbd5b11ac52f8a0f32d299624b6de0e17..ce77dac9a0202ae1c1f1a95fccc5419762b1e8c6 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 3f0718b4a7d28bb46f90db39eda863310b13e593..268627a17cf0d8165917fb818160c28809e45878 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 6cb8dae768fad303fdbefec803aae5e31d75e341..11b5c042d4faefc3b1cfca0092690635f85d3be3 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>
@@ -836,6 +837,34 @@ 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.
@@ -850,6 +879,12 @@ 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 1a426d7c1d0d73f6567289d8946e9f98096e0891..dc822124cacb9c8bef31971fb1de796f9556f4e9 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>