[Xen-devel] [PATCH 1/6] xen/pvh: Support ParaVirtualized Hardware extensions.

[Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>]

From: Mukesh Rathor <mukesh.rathor@xxxxxxxxxx>

PVH allows PV linux guest to utilize hardware extended capabilities, such
as running MMU updates in a HVM container.

This patch allows it to be configured and enabled. Also, basic header file
changes to add new subcalls to physmap hypercall.

Lastly, mfn_to_local_pfn must return mfn for paging mode translate
(since we let the hypervisor - or CPU - do them for us).

Signed-off-by: Mukesh Rathor <mukesh.rathor@xxxxxxxxxx>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
---
 arch/x86/include/asm/xen/page.h |    3 +++
 arch/x86/xen/Kconfig            |   10 ++++++++++
 arch/x86/xen/xen-head.S         |   11 ++++++++++-
 include/xen/interface/memory.h  |   24 +++++++++++++++++++++++-
 include/xen/interface/physdev.h |   10 ++++++++++
 5 files changed, 56 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h
index 472b9b7..6af440d 100644
--- a/arch/x86/include/asm/xen/page.h
+++ b/arch/x86/include/asm/xen/page.h
@@ -159,6 +159,9 @@ static inline xpaddr_t machine_to_phys(xmaddr_t machine)
 static inline unsigned long mfn_to_local_pfn(unsigned long mfn)
 {
        unsigned long pfn = mfn_to_pfn(mfn);
+
+       if (xen_feature(XENFEAT_auto_translated_physmap))
+               return mfn;
        if (get_phys_to_machine(pfn) != mfn)
                return -1; /* force !pfn_valid() */
        return pfn;
diff --git a/arch/x86/xen/Kconfig b/arch/x86/xen/Kconfig
index fdce49c..822c5a0 100644
--- a/arch/x86/xen/Kconfig
+++ b/arch/x86/xen/Kconfig
@@ -50,3 +50,13 @@ config XEN_DEBUG_FS
          Enable statistics output and various tuning options in debugfs.
          Enabling this option may incur a significant performance overhead.
 
+config XEN_X86_PVH
+       bool "Support for running as a PVH guest (EXPERIMENTAL)"
+       depends on X86_64 && XEN && EXPERIMENTAL
+       default n
+       help
+          This option enables support for running as a PVH guest (PV guest
+          using hardware extensions) under a suitably capable hypervisor.
+          This option is EXPERIMENTAL because the hypervisor interfaces
+          which it uses are not yet considered stable therefore backwards and
+          forwards compatibility is not yet guaranteed.  If unsure, say N.
diff --git a/arch/x86/xen/xen-head.S b/arch/x86/xen/xen-head.S
index 7faed58..1a6bca1 100644
--- a/arch/x86/xen/xen-head.S
+++ b/arch/x86/xen/xen-head.S
@@ -13,6 +13,15 @@
 #include <xen/interface/elfnote.h>
 #include <asm/xen/interface.h>
 
+#ifdef CONFIG_XEN_X86_PVH
+#define FEATURES_PVH "|writable_descriptor_tables" \
+                    "|auto_translated_physmap" \
+                    "|supervisor_mode_kernel" \
+                    "|hvm_callback_vector"
+#else
+#define FEATURES_PVH /* Not supported */
+#endif
+
        __INIT
 ENTRY(startup_xen)
        cld
@@ -95,7 +104,7 @@ NEXT_HYPERCALL(arch_6)
 #endif
        ELFNOTE(Xen, XEN_ELFNOTE_ENTRY,          _ASM_PTR startup_xen)
        ELFNOTE(Xen, XEN_ELFNOTE_HYPERCALL_PAGE, _ASM_PTR hypercall_page)
-       ELFNOTE(Xen, XEN_ELFNOTE_FEATURES,       .asciz 
"!writable_page_tables|pae_pgdir_above_4gb")
+       ELFNOTE(Xen, XEN_ELFNOTE_FEATURES,       .asciz 
"!writable_page_tables|pae_pgdir_above_4gb"FEATURES_PVH)
        ELFNOTE(Xen, XEN_ELFNOTE_PAE_MODE,       .asciz "yes")
        ELFNOTE(Xen, XEN_ELFNOTE_LOADER,         .asciz "generic")
        ELFNOTE(Xen, XEN_ELFNOTE_L1_MFN_VALID,
diff --git a/include/xen/interface/memory.h b/include/xen/interface/memory.h
index b66d04c..8beebdb 100644
--- a/include/xen/interface/memory.h
+++ b/include/xen/interface/memory.h
@@ -169,7 +169,13 @@ struct xen_add_to_physmap {
     /* Source mapping space. */
 #define XENMAPSPACE_shared_info 0 /* shared info page */
 #define XENMAPSPACE_grant_table 1 /* grant table page */
-    unsigned int space;
+#define XENMAPSPACE_gmfn        2 /* GMFN */
+#define XENMAPSPACE_gmfn_range  3 /* GMFN range */
+#define XENMAPSPACE_gmfn_foreign 4 /* GMFN from another guest */
+    uint16_t space;
+    domid_t foreign_domid;         /* IFF XENMAPSPACE_gmfn_foreign */
+
+#define XENMAPIDX_grant_table_status 0x80000000
 
     /* Index into source mapping space. */
     xen_ulong_t idx;
@@ -237,4 +243,20 @@ DEFINE_GUEST_HANDLE_STRUCT(xen_memory_map);
  * during a driver critical region.
  */
 extern spinlock_t xen_reservation_lock;
+
+/*
+ * Unmaps the page appearing at a particular GPFN from the specified guest's
+ * pseudophysical address space.
+ * arg == addr of xen_remove_from_physmap_t.
+ */
+#define XENMEM_remove_from_physmap      15
+struct xen_remove_from_physmap {
+    /* Which domain to change the mapping for. */
+    domid_t domid;
+
+    /* GPFN of the current mapping of the page. */
+    xen_pfn_t gpfn;
+};
+DEFINE_GUEST_HANDLE_STRUCT(xen_remove_from_physmap);
+
 #endif /* __XEN_PUBLIC_MEMORY_H__ */
diff --git a/include/xen/interface/physdev.h b/include/xen/interface/physdev.h
index 1844d31..83050d3 100644
--- a/include/xen/interface/physdev.h
+++ b/include/xen/interface/physdev.h
@@ -274,6 +274,16 @@ struct physdev_dbgp_op {
     } u;
 };
 
+#define PHYSDEVOP_map_iomem        30
+struct physdev_map_iomem {
+    /* IN */
+    uint64_t first_gfn;
+    uint64_t first_mfn;
+    uint32_t nr_mfns;
+    uint32_t add_mapping; /* 1 == add mapping;  0 == unmap */
+
+};
+
 /*
  * Notify that some PIRQ-bound event channels have been unmasked.
  * ** This command is obsolete since interface version 0x00030202 and is **
-- 
1.7.7.6


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