[PATCH 07/10] xen/pvh: bootup and setup (E820) related changes.

From: Konrad Rzeszutek Wilk
Date: Tue Oct 23 2012 - 14:26:36 EST

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.

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@xxxxxxxxxx>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
---
arch/x86/xen/enlighten.c | 77 ++++++++++++++++++++++++++++++++++-----------
arch/x86/xen/setup.c | 64 +++++++++++++++++++++++++++++++-------
2 files changed, 110 insertions(+), 31 deletions(-)

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index b679f86..bd8f718 100644
--- 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>
@@ -107,6 +108,9 @@ 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.
@@ -219,8 +223,9 @@ 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)" : "");
@@ -273,12 +278,15 @@ 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;
@@ -1055,6 +1063,10 @@ 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();
@@ -1292,6 +1304,11 @@ 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;

@@ -1302,6 +1319,19 @@ 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)
{
@@ -1313,13 +1343,18 @@ 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;
@@ -1351,8 +1386,6 @@ 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();
@@ -1423,14 +1456,18 @@ 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 */
@@ -1497,6 +1534,8 @@ asmlinkage void __init xen_start_kernel(void)
#endif
}

+/* Use a pfn in RAM, may move to MMIO before kexec.
+ * This function also called for PVH dom0 */
void __ref xen_hvm_init_shared_info(void)
{
int cpu;
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 8971a26..8cce47b 100644
--- 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)) {
--
1.7.7.6

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