Message-ID: <20121017173005.73a03eec@mantra.us.oracle.com>
Date:	Wed, 17 Oct 2012 17:30:05 -0700
From:	Mukesh Rathor <mukesh.rathor@...cle.com>
To:	Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>,
	"Xen-devel@...ts.xensource.com" <Xen-devel@...ts.xensource.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: [PATCH V3 2/6]: PVH: use native irq, enable callback, use HVM ring
 ops,  smp, ...

PVH: make gdt_frames[]/gdt_ents into a union with {gdtaddr, gdtsz}, PVH
only needs to send down gdtaddr and gdtsz. irq.c: PVH uses
native_irq_ops. vcpu hotplug is currently not available for PVH.
events.c: setup callback vector for PVH. smp.c: This pertains to
bringing up smp vcpus. PVH runs in ring 0, so syscalls are native.
Also, the vcpu context is send down via the hcall to be set in the
vmcs. gdtaddr and gdtsz are unionionized as PVH only needs to send
these two to be set in the vmcs. Finally, PVH ring ops uses HVM paths
for xenbus.

Signed-off-by: Mukesh Rathor <mukesh.rathor@...cle.com>
---
 arch/x86/include/asm/xen/interface.h |   11 +++++-
 arch/x86/xen/irq.c                   |    5 ++-
 arch/x86/xen/p2m.c                   |    2 +-
 arch/x86/xen/smp.c                   |   75
++++++++++++++++++++++------------ drivers/xen/cpu_hotplug.c
|    4 +- drivers/xen/events.c                 |    9 ++++-
 drivers/xen/xenbus/xenbus_client.c   |    3 +-
 7 files changed, 77 insertions(+), 32 deletions(-)

diff --git a/arch/x86/include/asm/xen/interface.h
b/arch/x86/include/asm/xen/interface.h index 555f94d..ac5ef76 100644
--- a/arch/x86/include/asm/xen/interface.h
+++ b/arch/x86/include/asm/xen/interface.h
@@ -143,7 +143,16 @@ struct vcpu_guest_context {
     struct cpu_user_regs user_regs;         /* User-level CPU
registers     */ struct trap_info trap_ctxt[256];        /* Virtual
IDT                  */ unsigned long ldt_base, ldt_ents;       /* LDT
(linear address, # ents) */
-    unsigned long gdt_frames[16], gdt_ents; /* GDT (machine frames, #
ents) */
+    union {
+	struct {
+		/* PV: GDT (machine frames, # ents).*/
+		unsigned long gdt_frames[16], gdt_ents;
+	} pv;
+	struct {
+		/* PVH: GDTR addr and size */
+	    unsigned long gdtaddr, gdtsz;
+	} pvh;
+    } u;
     unsigned long kernel_ss, kernel_sp;     /* Virtual TSS (only
SS1/SP1)   */ /* NB. User pagetable on x86/64 is placed in ctrlreg[1].
*/ unsigned long ctrlreg[8];               /* CR0-CR7 (control
registers)  */ diff --git a/arch/x86/xen/irq.c b/arch/x86/xen/irq.c
index 1573376..31959a7 100644
--- a/arch/x86/xen/irq.c
+++ b/arch/x86/xen/irq.c
@@ -5,6 +5,7 @@
 #include <xen/interface/xen.h>
 #include <xen/interface/sched.h>
 #include <xen/interface/vcpu.h>
+#include <xen/features.h>
 
 #include <asm/xen/hypercall.h>
 #include <asm/xen/hypervisor.h>
@@ -128,6 +129,8 @@ static const struct pv_irq_ops xen_irq_ops
__initconst = { 
 void __init xen_init_irq_ops(void)
 {
-	pv_irq_ops = xen_irq_ops;
+	/* For PVH we use default pv_irq_ops settings */
+	if (!xen_feature(XENFEAT_hvm_callback_vector))
+		pv_irq_ops = xen_irq_ops;
 	x86_init.irqs.intr_init = xen_init_IRQ;
 }
diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index 95fb2aa..ea553c8 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -798,7 +798,7 @@ bool __set_phys_to_machine(unsigned long pfn,
unsigned long mfn) {
 	unsigned topidx, mididx, idx;
 
-	if (unlikely(xen_feature(XENFEAT_auto_translated_physmap))) {
+	if (xen_feature(XENFEAT_auto_translated_physmap)) {
 		BUG_ON(pfn != mfn && mfn != INVALID_P2M_ENTRY);
 		return true;
 	}
diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index f58dca7..cda1907 100644
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -68,9 +68,11 @@ static void __cpuinit cpu_bringup(void)
 	touch_softlockup_watchdog();
 	preempt_disable();
 
-	xen_enable_sysenter();
-	xen_enable_syscall();
-
+	/* PVH runs in ring 0 and allows us to do native syscalls.
Yay! */
+	if (!xen_feature(XENFEAT_supervisor_mode_kernel)) {
+		xen_enable_sysenter();
+		xen_enable_syscall();
+	}
 	cpu = smp_processor_id();
 	smp_store_cpu_info(cpu);
 	cpu_data(cpu).x86_max_cores = 1;
@@ -230,10 +232,11 @@ static void __init xen_smp_prepare_boot_cpu(void)
 	BUG_ON(smp_processor_id() != 0);
 	native_smp_prepare_boot_cpu();
 
-	/* We've switched to the "real" per-cpu gdt, so make sure the
-	   old memory can be recycled */
-	make_lowmem_page_readwrite(xen_initial_gdt);
-
+	if (!xen_feature(XENFEAT_writable_page_tables)) {
+		/* We've switched to the "real" per-cpu gdt, so make
sure the
+		 * old memory can be recycled */
+		make_lowmem_page_readwrite(xen_initial_gdt);
+	}
 	xen_filter_cpu_maps();
 	xen_setup_vcpu_info_placement();
 }
@@ -300,8 +303,6 @@ cpu_initialize_context(unsigned int cpu, struct
task_struct *idle) gdt = get_cpu_gdt_table(cpu);
 
 	ctxt->flags = VGCF_IN_KERNEL;
-	ctxt->user_regs.ds = __USER_DS;
-	ctxt->user_regs.es = __USER_DS;
 	ctxt->user_regs.ss = __KERNEL_DS;
 #ifdef CONFIG_X86_32
 	ctxt->user_regs.fs = __KERNEL_PERCPU;
@@ -310,35 +311,57 @@ cpu_initialize_context(unsigned int cpu, struct
task_struct *idle) ctxt->gs_base_kernel = per_cpu_offset(cpu);
 #endif
 	ctxt->user_regs.eip = (unsigned long)cpu_bringup_and_idle;
-	ctxt->user_regs.eflags = 0x1000; /* IOPL_RING1 */
 
 	memset(&ctxt->fpu_ctxt, 0, sizeof(ctxt->fpu_ctxt));
 
-	xen_copy_trap_info(ctxt->trap_ctxt);
+	/* check for autoxlated to get it right for 32bit kernel */
+	if (xen_feature(XENFEAT_auto_translated_physmap) &&
+	    xen_feature(XENFEAT_supervisor_mode_kernel)) {
 
-	ctxt->ldt_ents = 0;
+		ctxt->user_regs.ds = __KERNEL_DS;
+		ctxt->user_regs.es = 0;
+		ctxt->user_regs.gs = 0;
 
-	BUG_ON((unsigned long)gdt & ~PAGE_MASK);
+		ctxt->u.pvh.gdtaddr = (unsigned long)gdt;
+		ctxt->u.pvh.gdtsz = (unsigned long)(GDT_SIZE - 1);
 
-	gdt_mfn = arbitrary_virt_to_mfn(gdt);
-	make_lowmem_page_readonly(gdt);
-	make_lowmem_page_readonly(mfn_to_virt(gdt_mfn));
+#ifdef CONFIG_X86_64
+		/* Note: PVH is not supported on x86_32. */
+		ctxt->gs_base_user = (unsigned long)
+
per_cpu(irq_stack_union.gs_base, cpu); +#endif
+	} else {
+		ctxt->user_regs.eflags = 0x1000; /* IOPL_RING1 */
+		ctxt->user_regs.ds = __USER_DS;
+		ctxt->user_regs.es = __USER_DS;
 
-	ctxt->gdt_frames[0] = gdt_mfn;
-	ctxt->gdt_ents      = GDT_ENTRIES;
+		xen_copy_trap_info(ctxt->trap_ctxt);
 
-	ctxt->user_regs.cs = __KERNEL_CS;
-	ctxt->user_regs.esp = idle->thread.sp0 - sizeof(struct
pt_regs);
+		ctxt->ldt_ents = 0;
 
-	ctxt->kernel_ss = __KERNEL_DS;
-	ctxt->kernel_sp = idle->thread.sp0;
+		BUG_ON((unsigned long)gdt & ~PAGE_MASK);
+
+		gdt_mfn = arbitrary_virt_to_mfn(gdt);
+		make_lowmem_page_readonly(gdt);
+		make_lowmem_page_readonly(mfn_to_virt(gdt_mfn));
+
+		ctxt->u.pv.gdt_frames[0] = gdt_mfn;
+		ctxt->u.pv.gdt_ents      = GDT_ENTRIES;
+
+		ctxt->kernel_ss = __KERNEL_DS;
+		ctxt->kernel_sp = idle->thread.sp0;
 
 #ifdef CONFIG_X86_32
-	ctxt->event_callback_cs     = __KERNEL_CS;
-	ctxt->failsafe_callback_cs  = __KERNEL_CS;
+		ctxt->event_callback_cs     = __KERNEL_CS;
+		ctxt->failsafe_callback_cs  = __KERNEL_CS;
 #endif
-	ctxt->event_callback_eip    = (unsigned
long)xen_hypervisor_callback;
-	ctxt->failsafe_callback_eip = (unsigned
long)xen_failsafe_callback;
+		ctxt->event_callback_eip    =
+					(unsigned
long)xen_hypervisor_callback;
+		ctxt->failsafe_callback_eip =
+					(unsigned
long)xen_failsafe_callback;
+	}
+	ctxt->user_regs.cs = __KERNEL_CS;
+	ctxt->user_regs.esp = idle->thread.sp0 - sizeof(struct
pt_regs); 
 	per_cpu(xen_cr3, cpu) = __pa(swapper_pg_dir);
 	ctxt->ctrlreg[3] = xen_pfn_to_cr3(virt_to_mfn(swapper_pg_dir));
diff --git a/drivers/xen/cpu_hotplug.c b/drivers/xen/cpu_hotplug.c
index 4dcfced..de6bcf9 100644
--- a/drivers/xen/cpu_hotplug.c
+++ b/drivers/xen/cpu_hotplug.c
@@ -2,6 +2,7 @@
 
 #include <xen/xen.h>
 #include <xen/xenbus.h>
+#include <xen/features.h>
 
 #include <asm/xen/hypervisor.h>
 #include <asm/cpu.h>
@@ -100,7 +101,8 @@ static int __init setup_vcpu_hotplug_event(void)
 	static struct notifier_block xsn_cpu = {
 		.notifier_call = setup_cpu_watcher };
 
-	if (!xen_pv_domain())
+	/* PVH TBD/FIXME: future work */
+	if (!xen_pv_domain() ||
xen_feature(XENFEAT_auto_translated_physmap)) return -ENODEV;
 
 	register_xenstore_notifier(&xsn_cpu);
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index c60d162..a977612 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -1767,7 +1767,7 @@ int xen_set_callback_via(uint64_t via)
 }
 EXPORT_SYMBOL_GPL(xen_set_callback_via);
 
-#ifdef CONFIG_XEN_PVHVM
+#ifdef CONFIG_X86
 /* Vector callbacks are better than PCI interrupts to receive event
  * channel notifications because we can receive vector callbacks on any
  * vcpu and we don't need PCI support or APIC interactions. */
@@ -1826,6 +1826,13 @@ void __init xen_init_IRQ(void)
 		if (xen_initial_domain())
 			pci_xen_initial_domain();
 
+		if (xen_feature(XENFEAT_hvm_callback_vector)) {
+			xen_callback_vector();
+			return;
+		}
+
+		/* PVH: TBD/FIXME: debug and fix eio map to work with
pvh */ +
 		pirq_eoi_map = (void
*)__get_free_page(GFP_KERNEL|__GFP_ZERO); eoi_gmfn.gmfn =
virt_to_mfn(pirq_eoi_map); rc =
HYPERVISOR_physdev_op(PHYSDEVOP_pirq_eoi_gmfn_v2, &eoi_gmfn); diff
--git a/drivers/xen/xenbus/xenbus_client.c
b/drivers/xen/xenbus/xenbus_client.c index b3e146e..1bac743 100644 ---
a/drivers/xen/xenbus/xenbus_client.c +++
b/drivers/xen/xenbus/xenbus_client.c @@ -44,6 +44,7 @@
 #include <xen/grant_table.h>
 #include <xen/xenbus.h>
 #include <xen/xen.h>
+#include <xen/features.h>
 
 #include "xenbus_probe.h"
 
@@ -743,7 +744,7 @@ static const struct xenbus_ring_ops ring_ops_hvm = {
 
 void __init xenbus_ring_ops_init(void)
 {
-	if (xen_pv_domain())
+	if (xen_pv_domain()
&& !xen_feature(XENFEAT_auto_translated_physmap)) ring_ops =
&ring_ops_pv; else
 		ring_ops = &ring_ops_hvm;
-- 
1.7.2.3

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