xen/pvh: bootup and setup (E820) related changes.

In the bootup code for PVH we can trap cpuid via vmexit, so don't
need to use emulated prefix call. We also check for vector callback
early on, as it is a required feature. PVH also runs at default kernel
IOPL.

In setup.c which deals with E820, in xen_add_extra_mem() we can skip
updating P2M as it's managed by Xen. PVH maps the entire IO space,
but only RAM pages need to be repopulated.

Finally, pure PV settings are moved to a separate function that are
only called for pure PV, ie, pv with pvmmu.

Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[ ijc -- rebase onto xen PVonHVM: use E820_Reserved area for
         shared_info ]

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 3aeaa933b5278cc48944aaa4eeb9fdfaffcade50..c93b94a8475c46f8e469fa0aaf91defff34d37e1 100644 (file)
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -45,6 +45,7 @@
 #include <xen/hvm.h>
 #include <xen/hvc-console.h>
 #include <xen/acpi.h>
+#include <xen/features.h>
 
 #include <asm/paravirt.h>
 #include <asm/apic.h>
@@ -105,6 +106,9 @@ RESERVE_BRK(shared_info_page_brk, PAGE_SIZE);
 __read_mostly int xen_have_vector_callback;
 EXPORT_SYMBOL_GPL(xen_have_vector_callback);
 
+#define xen_pvh_domain() (xen_pv_domain() && \
+                         xen_feature(XENFEAT_auto_translated_physmap) && \
+                         xen_have_vector_callback)
 /*
  * Point at some empty memory to start with. We map the real shared_info
  * page as soon as fixmap is up and running.
@@ -217,8 +221,9 @@ static void __init xen_banner(void)
        struct xen_extraversion extra;
        HYPERVISOR_xen_version(XENVER_extraversion, &extra);
 
-       printk(KERN_INFO "Booting paravirtualized kernel on %s\n",
-              pv_info.name);
+       pr_info("Booting paravirtualized kernel %son %s\n",
+               xen_feature(XENFEAT_auto_translated_physmap) ?
+                       "with PVH extensions " : "", pv_info.name);
        printk(KERN_INFO "Xen version: %d.%d%s%s\n",
               version >> 16, version & 0xffff, extra.extraversion,
               xen_feature(XENFEAT_mmu_pt_update_preserve_ad) ? " (preserve-AD)" : "");
@@ -286,12 +291,15 @@ static void xen_cpuid(unsigned int *ax, unsigned int *bx,
                break;
        }
 
-       asm(XEN_EMULATE_PREFIX "cpuid"
-               : "=a" (*ax),
-                 "=b" (*bx),
-                 "=c" (*cx),
-                 "=d" (*dx)
-               : "0" (*ax), "2" (*cx));
+       if (xen_pvh_domain())
+               native_cpuid(ax, bx, cx, dx);
+       else
+               asm(XEN_EMULATE_PREFIX "cpuid"
+                       : "=a" (*ax),
+                       "=b" (*bx),
+                       "=c" (*cx),
+                       "=d" (*dx)
+                       : "0" (*ax), "2" (*cx));
 
        *bx &= maskebx;
        *cx &= maskecx;
@@ -1074,6 +1082,10 @@ void xen_setup_shared_info(void)
                HYPERVISOR_shared_info =
                        (struct shared_info *)__va(xen_start_info->shared_info);
 
+       /* PVH TBD/FIXME: vcpu info placement in phase 2 */
+       if (xen_pvh_domain())
+               return;
+
 #ifndef CONFIG_SMP
        /* In UP this is as good a place as any to set up shared info */
        xen_setup_vcpu_info_placement();
@@ -1311,6 +1323,11 @@ static const struct machine_ops xen_machine_ops __initconst = {
  */
 static void __init xen_setup_stackprotector(void)
 {
+       /* PVH TBD/FIXME: investigate setup_stack_canary_segment */
+       if (xen_feature(XENFEAT_auto_translated_physmap)) {
+               switch_to_new_gdt(0);
+               return;
+       }
        pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry_boot;
        pv_cpu_ops.load_gdt = xen_load_gdt_boot;
 
@@ -1321,6 +1338,19 @@ static void __init xen_setup_stackprotector(void)
        pv_cpu_ops.load_gdt = xen_load_gdt;
 }
 
+static void __init xen_pvh_early_guest_init(void)
+{
+       if (xen_feature(XENFEAT_hvm_callback_vector))
+               xen_have_vector_callback = 1;
+
+#ifdef CONFIG_X86_32
+       if (xen_feature(XENFEAT_auto_translated_physmap)) {
+               xen_raw_printk("ERROR: 32bit PVH guests are not supported\n");
+               BUG();
+       }
+#endif
+}
+
 /* First C function to be called on Xen boot */
 asmlinkage void __init xen_start_kernel(void)
 {
@@ -1332,13 +1362,18 @@ asmlinkage void __init xen_start_kernel(void)
 
        xen_domain_type = XEN_PV_DOMAIN;
 
+       xen_setup_features();
+       xen_pvh_early_guest_init();
        xen_setup_machphys_mapping();
 
        /* Install Xen paravirt ops */
        pv_info = xen_info;
        pv_init_ops = xen_init_ops;
-       pv_cpu_ops = xen_cpu_ops;
        pv_apic_ops = xen_apic_ops;
+       if (xen_pvh_domain())
+               pv_cpu_ops.cpuid = xen_cpuid;
+       else
+               pv_cpu_ops = xen_cpu_ops;
 
        x86_init.resources.memory_setup = xen_memory_setup;
        x86_init.oem.arch_setup = xen_arch_setup;
@@ -1370,8 +1405,6 @@ asmlinkage void __init xen_start_kernel(void)
        /* Work out if we support NX */
        x86_configure_nx();
 
-       xen_setup_features();
-
        /* Get mfn list */
        if (!xen_feature(XENFEAT_auto_translated_physmap))
                xen_build_dynamic_phys_to_machine();
@@ -1442,14 +1475,18 @@ asmlinkage void __init xen_start_kernel(void)
        /* set the limit of our address space */
        xen_reserve_top();
 
-       /* We used to do this in xen_arch_setup, but that is too late on AMD
-        * were early_cpu_init (run before ->arch_setup()) calls early_amd_init
-        * which pokes 0xcf8 port.
-        */
-       set_iopl.iopl = 1;
-       rc = HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
-       if (rc != 0)
-               xen_raw_printk("physdev_op failed %d\n", rc);
+       /* PVH: runs at default kernel iopl of 0 */
+       if (!xen_pvh_domain()) {
+               /*
+                * We used to do this in xen_arch_setup, but that is too late
+                * on AMD were early_cpu_init (run before ->arch_setup()) calls
+                * early_amd_init which pokes 0xcf8 port.
+                */
+               set_iopl.iopl = 1;
+               rc = HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
+               if (rc != 0)
+                       xen_raw_printk("physdev_op failed %d\n", rc);
+       }
 
 #ifdef CONFIG_X86_32
        /* set up basic CPUID stuff */
@@ -1522,6 +1559,8 @@ static struct shared_info *xen_hvm_shared_info;
 static unsigned long xen_hvm_sip_phys;
 static int xen_major, xen_minor;
 
+/* Use a pfn in RAM, may move to MMIO before kexec.
+ * This function also called for PVH dom0 */
 static void xen_hvm_connect_shared_info(unsigned long pfn)
 {
        struct xen_add_to_physmap xatp;

diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 8971a26d21abb943d5c9e23b5c6630a207f43536..8cce47b98d5efe9435ba4432e0bf9ae51d9ba7e9 100644 (file)
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -27,6 +27,7 @@
 #include <xen/interface/memory.h>
 #include <xen/interface/physdev.h>
 #include <xen/features.h>
+#include "mmu.h"
 #include "xen-ops.h"
 #include "vdso.h"
 
@@ -78,6 +79,9 @@ static void __init xen_add_extra_mem(u64 start, u64 size)
 
        memblock_reserve(start, size);
 
+       if (xen_feature(XENFEAT_auto_translated_physmap))
+               return;
+
        xen_max_p2m_pfn = PFN_DOWN(start + size);
        for (pfn = PFN_DOWN(start); pfn < xen_max_p2m_pfn; pfn++) {
                unsigned long mfn = pfn_to_mfn(pfn);
@@ -100,6 +104,7 @@ static unsigned long __init xen_do_chunk(unsigned long start,
                .domid        = DOMID_SELF
        };
        unsigned long len = 0;
+       int xlated_phys = xen_feature(XENFEAT_auto_translated_physmap);
        unsigned long pfn;
        int ret;
 
@@ -113,7 +118,7 @@ static unsigned long __init xen_do_chunk(unsigned long start,
                                continue;
                        frame = mfn;
                } else {
-                       if (mfn != INVALID_P2M_ENTRY)
+                       if (!xlated_phys && mfn != INVALID_P2M_ENTRY)
                                continue;
                        frame = pfn;
                }
@@ -230,6 +235,27 @@ static void __init xen_set_identity_and_release_chunk(
        *identity += set_phys_range_identity(start_pfn, end_pfn);
 }
 
+/* For PVH, the pfns [0..MAX] are mapped to mfn's in the EPT/NPT. The mfns
+ * are released as part of this 1:1 mapping hypercall back to the dom heap.
+ * Also, we map the entire IO space, ie, beyond max_pfn_mapped.
+ */
+static void __init xen_pvh_identity_map_chunk(unsigned long start_pfn,
+               unsigned long end_pfn, unsigned long *released,
+               unsigned long *identity, unsigned long max_pfn)
+{
+       unsigned long pfn;
+       int numpfns = 1, add_mapping = 1;
+
+       for (pfn = start_pfn; pfn < end_pfn; pfn++)
+               xen_set_clr_mmio_pvh_pte(pfn, pfn, numpfns, add_mapping);
+
+       if (start_pfn <= max_pfn) {
+               unsigned long end = min(max_pfn_mapped, end_pfn);
+               *released += end - start_pfn;
+       }
+       *identity += end_pfn - start_pfn;
+}
+
 static unsigned long __init xen_set_identity_and_release(
        const struct e820entry *list, size_t map_size, unsigned long nr_pages)
 {
@@ -238,6 +264,7 @@ static unsigned long __init xen_set_identity_and_release(
        unsigned long identity = 0;
        const struct e820entry *entry;
        int i;
+       int xlated_phys = xen_feature(XENFEAT_auto_translated_physmap);
 
        /*
         * Combine non-RAM regions and gaps until a RAM region (or the
@@ -259,11 +286,17 @@ static unsigned long __init xen_set_identity_and_release(
                        if (entry->type == E820_RAM)
                                end_pfn = PFN_UP(entry->addr);
 
-                       if (start_pfn < end_pfn)
-                               xen_set_identity_and_release_chunk(
-                                       start_pfn, end_pfn, nr_pages,
-                                       &released, &identity);
-
+                       if (start_pfn < end_pfn) {
+                               if (xlated_phys) {
+                                       xen_pvh_identity_map_chunk(start_pfn,
+                                               end_pfn, &released, &identity,
+                                               nr_pages);
+                               } else {
+                                       xen_set_identity_and_release_chunk(
+                                               start_pfn, end_pfn, nr_pages,
+                                               &released, &identity);
+                               }
+                       }
                        start = end;
                }
        }
@@ -526,16 +559,14 @@ void __cpuinit xen_enable_syscall(void)
 #endif /* CONFIG_X86_64 */
 }
 
-void __init xen_arch_setup(void)
+/* Non auto translated PV domain, ie, it's not PVH. */
+static __init void xen_pvmmu_arch_setup(void)
 {
-       xen_panic_handler_init();
-
        HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_4gb_segments);
        HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables);
 
-       if (!xen_feature(XENFEAT_auto_translated_physmap))
-               HYPERVISOR_vm_assist(VMASST_CMD_enable,
-                                    VMASST_TYPE_pae_extended_cr3);
+       HYPERVISOR_vm_assist(VMASST_CMD_enable,
+                            VMASST_TYPE_pae_extended_cr3);
 
        if (register_callback(CALLBACKTYPE_event, xen_hypervisor_callback) ||
            register_callback(CALLBACKTYPE_failsafe, xen_failsafe_callback))
@@ -543,6 +574,15 @@ void __init xen_arch_setup(void)
 
        xen_enable_sysenter();
        xen_enable_syscall();
+}
+
+/* This function not called for HVM domain */
+void __init xen_arch_setup(void)
+{
+       xen_panic_handler_init();
+
+       if (!xen_feature(XENFEAT_auto_translated_physmap))
+               xen_pvmmu_arch_setup();
 
 #ifdef CONFIG_ACPI
        if (!(xen_start_info->flags & SIF_INITDOMAIN)) {