[PATCH v13 03/19] xen/pvh: Early bootup changes in PV code (v4).

From: Konrad Rzeszutek Wilk
Date: Fri Jan 03 2014 - 15:38:26 EST


From: Mukesh Rathor <mukesh.rathor@xxxxxxxxxx>

We don't use the filtering that 'xen_cpuid' is doing
because the hypervisor treats 'XEN_EMULATE_PREFIX' as
an invalid instruction. This means that all of the filtering
will have to be done in the hypervisor/toolstack.

Without the filtering we expose to the guest the:

- cpu topology (sockets, cores, etc);
- the APERF (which the generic scheduler likes to
use), see 5e626254206a709c6e937f3dda69bf26c7344f6f
"xen/setup: filter APERFMPERF cpuid feature out"
- and the inability to figure out whether MWAIT_LEAF
should be exposed or not. See
df88b2d96e36d9a9e325bfcd12eb45671cbbc937
"xen/enlighten: Disable MWAIT_LEAF so that acpi-pad won't be loaded."
- x2apic, see 4ea9b9aca90cfc71e6872ed3522356755162932c
"xen: mask x2APIC feature in PV"

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 | 48 ++++++++++++++++++++++++++++++++++--------------
arch/x86/xen/setup.c | 18 ++++++++++++------
2 files changed, 46 insertions(+), 20 deletions(-)

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index fa6ade7..eb0efc2 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)" : "");
@@ -433,7 +435,7 @@ static void __init xen_init_cpuid_mask(void)

ax = 1;
cx = 0;
- xen_cpuid(&ax, &bx, &cx, &dx);
+ cpuid(1, &ax, &bx, &cx, &dx);

xsave_mask =
(1 << (X86_FEATURE_XSAVE % 32)) |
@@ -1420,6 +1422,19 @@ 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 +1446,16 @@ 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 = xen_cpu_ops;

x86_init.resources.memory_setup = xen_memory_setup;
x86_init.oem.arch_setup = xen_arch_setup;
@@ -1469,8 +1487,6 @@ 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 +1564,18 @@ 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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