[PATCH v2 5/6] xen/x86/pvh: Add 32-bit PVH initialization code

From: Boris Ostrovsky <boris.ostrovsky@oracle.com>
To: david.vrabel@citrix.com, konrad.wilk@oracle.com
Cc: elena.ufimtseva@oracle.com, ian.campbell@citrix.com,
	stefano.stabellini@eu.citrix.com, andrew.cooper3@citrix.com,
	tim@xen.org, linux-kernel@vger.kernel.org, jbeulich@suse.com,
	xen-devel@lists.xenproject.org, boris.ostrovsky@oracle.com,
	ian.jackson@eu.citrix.com, roger.pau@citrix.com
Subject: [PATCH v2 5/6] xen/x86/pvh: Add 32-bit PVH initialization code
Date: Thu, 16 Jul 2015 17:43:40 -0400	[thread overview]
Message-ID: <1437083021-24488-6-git-send-email-boris.ostrovsky__45811.8998133161$1437083125$gmane$org@oracle.com> (raw)
In-Reply-To: <1437083021-24488-1-git-send-email-boris.ostrovsky@oracle.com>

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
---
Changes in v2:
* Some code reshuffling due to changes in patch 1.

 arch/x86/xen/enlighten.c |  4 ----
 arch/x86/xen/smp.c       | 16 +++++++++-------
 arch/x86/xen/xen-head.S  | 13 ++++++++++++-
 3 files changed, 21 insertions(+), 12 deletions(-)

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index d665b1d..9eb395f 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1461,10 +1461,6 @@ static void __init xen_pvh_early_guest_init(void)
 
 	xen_pvh_early_cpu_init(0);
 	xen_pvh_set_cr_flags(0);
-
-#ifdef CONFIG_X86_32
-	BUG(); /* PVH: Implement proper support. */
-#endif
 }
 #endif    /* CONFIG_XEN_PVH */
 
diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index 33a4529..f8c5d23 100644
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -372,11 +372,8 @@ cpu_initialize_context(unsigned int cpu, struct task_struct *idle)
 
 	gdt = get_cpu_gdt_table(cpu);
 
-#ifdef CONFIG_X86_32
-	/* Note: PVH is not yet supported on x86_32. */
-	ctxt->user_regs.fs = __KERNEL_PERCPU;
-	ctxt->user_regs.gs = __KERNEL_STACK_CANARY;
-#endif
+	ctxt->user_regs.esp = idle->thread.sp0 - sizeof(struct pt_regs);
+	ctxt->ctrlreg[3] = xen_pfn_to_cr3(virt_to_mfn(swapper_pg_dir));
 
 	if (!xen_feature(XENFEAT_auto_translated_physmap)) {
 		ctxt->user_regs.eip = (unsigned long)cpu_bringup_and_idle;
@@ -403,6 +400,8 @@ cpu_initialize_context(unsigned int cpu, struct task_struct *idle)
 		ctxt->kernel_sp = idle->thread.sp0;
 
 #ifdef CONFIG_X86_32
+		ctxt->user_regs.fs = __KERNEL_PERCPU;
+		ctxt->user_regs.gs = __KERNEL_STACK_CANARY;
 		ctxt->event_callback_cs     = __KERNEL_CS;
 		ctxt->failsafe_callback_cs  = __KERNEL_CS;
 #else
@@ -424,11 +423,14 @@ cpu_initialize_context(unsigned int cpu, struct task_struct *idle)
 		 */
 		ctxt->user_regs.eip =
 			(unsigned long)xen_pvh_early_cpu_init_secondary;
+#ifdef CONFIG_X86_64
 		ctxt->user_regs.rdi = cpu;
+#else
+		*((uint32_t *)ctxt->user_regs.esp + 1) = cpu;
+#endif
 	}
 #endif
-	ctxt->user_regs.esp = idle->thread.sp0 - sizeof(struct pt_regs);
-	ctxt->ctrlreg[3] = xen_pfn_to_cr3(virt_to_mfn(swapper_pg_dir));
+
 	if (HYPERVISOR_vcpu_op(VCPUOP_initialise, cpu, ctxt))
 		BUG();
 
diff --git a/arch/x86/xen/xen-head.S b/arch/x86/xen/xen-head.S
index 944b08b..eada11b 100644
--- a/arch/x86/xen/xen-head.S
+++ b/arch/x86/xen/xen-head.S
@@ -55,7 +55,11 @@ ENTRY(startup_xen)
  * @cpu:   this cpu number (%rdi)
  */
 ENTRY(xen_pvh_early_cpu_init)
+#ifdef CONFIG_X86_64
 	mov	%rbx, -8(%rsp)
+#else
+	mov	%ebx, -4(%esp)
+#endif
 	xor	%esi, %esi
 	jmp	1f
 
@@ -70,13 +74,20 @@ ENTRY(xen_pvh_early_cpu_init_secondary)
 
 	mov     $MSR_EFER, %ecx
 	rdmsr
+#ifdef CONFIG_X86_64
 	bts     $_EFER_SCE, %eax
-
+#endif
 	bt      $20, %ebx
 	jnc     2f      	/* No NX, skip setting it */
 	bts     $_EFER_NX, %eax
 2:	wrmsr
+
+#ifdef CONFIG_X86_64
 	mov	-8(%rsp), %rbx
+#else
+	mov	-4(%esp), %ebx
+#endif
+
 #ifdef CONFIG_SMP
 	cmp     $0, %esi
 	jne     cpu_bringup_and_idle
-- 
1.8.1.4
