[Xen-devel] [PATCH v12 03/18] xen/pvh: Early bootup changes in PV code (v2).

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

From: Mukesh Rathor <mukesh.rathor@xxxxxxxxxx>

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.

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

Signed-off-by: Mukesh Rathor <mukesh.rathor@xxxxxxxxxx>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
---
 arch/x86/xen/enlighten.c | 63 +++++++++++++++++++++++++++++++++---------------
 arch/x86/xen/setup.c     | 18 +++++++++-----
 2 files changed, 56 insertions(+), 25 deletions(-)

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index fa6ade7..755e5bb 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -46,6 +46,7 @@
 #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>
@@ -262,8 +263,9 @@ 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)" : "");
@@ -331,12 +333,15 @@ 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;
@@ -1420,6 +1425,19 @@ 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_auto_translated_physmap))
+               return;
+
+       if (xen_feature(XENFEAT_hvm_callback_vector))
+               xen_have_vector_callback = 1;
+
+#ifdef CONFIG_X86_32
+       BUG(); /* PVH: Implement proper support. */
+#endif
+}
+
 /* First C function to be called on Xen boot */
 asmlinkage void __init xen_start_kernel(void)
 {
@@ -1431,13 +1449,18 @@ 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;
@@ -1469,8 +1492,6 @@ 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();
@@ -1548,14 +1569,18 @@ 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 */
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 68c054f..2137c51 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -563,16 +563,13 @@ void xen_enable_nmi(void)
                BUG();
 #endif
 }
-void __init xen_arch_setup(void)
+void __init 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))
@@ -581,6 +578,15 @@ void __init xen_arch_setup(void)
        xen_enable_sysenter();
        xen_enable_syscall();
        xen_enable_nmi();
+}
+
+/* This function is not called for HVM domains */
+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)) {
                printk(KERN_INFO "ACPI in unprivileged domain disabled\n");
-- 
1.8.3.1


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