[PATCH v1 08/12] xen/hvmlite: Initialize context for secondary VCPUs

From: Boris Ostrovsky
Date: Fri Jan 22 2016 - 16:37:04 EST


Signed-off-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
---
arch/x86/xen/smp.c | 57 ++++++++++++++++++++++++++++++++++++++++----
arch/x86/xen/smp.h | 4 +++
arch/x86/xen/xen-hvmlite.S | 7 +++++
3 files changed, 63 insertions(+), 5 deletions(-)

diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index 5fc4afb..b265c4f 100644
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -27,6 +27,7 @@
#include <xen/interface/xen.h>
#include <xen/interface/vcpu.h>
#include <xen/interface/xenpmu.h>
+#include <xen/interface/hvm/hvm_vcpu.h>

#include <asm/xen/interface.h>
#include <asm/xen/hypercall.h>
@@ -384,6 +385,7 @@ cpu_initialize_context(unsigned int cpu, struct task_struct *idle)
struct vcpu_guest_context *ctxt;
struct desc_struct *gdt;
unsigned long gdt_mfn;
+ void *ctxt_arg;

/* used to tell cpu_init() that it can proceed with initialization */
cpumask_set_cpu(cpu, cpu_callout_mask);
@@ -392,7 +394,7 @@ cpu_initialize_context(unsigned int cpu, struct task_struct *idle)

if (!xen_hvmlite) {

- ctxt = kzalloc(sizeof(*ctxt), GFP_KERNEL);
+ ctxt_arg = ctxt = kzalloc(sizeof(*ctxt), GFP_KERNEL);
if (ctxt == NULL)
return -ENOMEM;

@@ -460,14 +462,59 @@ cpu_initialize_context(unsigned int cpu, struct task_struct *idle)
ctxt->user_regs.esp = idle->thread.sp0 - sizeof(struct pt_regs);
ctxt->ctrlreg[3] = xen_pfn_to_cr3(virt_to_gfn(swapper_pg_dir));
} else {
- ctxt = NULL; /* To quiet down compiler */
- BUG();
+#ifdef CONFIG_XEN_PVHVM
+ struct vcpu_hvm_context *hctxt;
+
+ ctxt_arg = hctxt = kzalloc(sizeof(*hctxt), GFP_KERNEL);
+ if (hctxt == NULL)
+ return -ENOMEM;
+
+#ifdef CONFIG_X86_64
+ hctxt->mode = VCPU_HVM_MODE_64B;
+ hctxt->cpu_regs.x86_64.rip =
+ (unsigned long)secondary_startup_64;
+ hctxt->cpu_regs.x86_64.rsp = stack_start;
+
+ hctxt->cpu_regs.x86_64.cr0 =
+ X86_CR0_PG | X86_CR0_WP | X86_CR0_PE;
+ hctxt->cpu_regs.x86_64.cr4 = X86_CR4_PAE;
+ hctxt->cpu_regs.x86_64.cr3 =
+ xen_pfn_to_cr3(virt_to_mfn(init_level4_pgt));
+ hctxt->cpu_regs.x86_64.efer = EFER_LME | EFER_NX;
+#else
+ hctxt->mode = VCPU_HVM_MODE_32B;
+ /*
+ * startup_32_smp expects GDT loaded so we can't jump
+ * there directly.
+ */
+ hctxt->cpu_regs.x86_32.eip =
+ (unsigned long)hvmlite_smp_32 - __START_KERNEL_map;
+
+ hctxt->cpu_regs.x86_32.cr0 = X86_CR0_PE;
+
+ hctxt->cpu_regs.x86_32.cs_base = 0;
+ hctxt->cpu_regs.x86_32.cs_limit = ~0u;
+ hctxt->cpu_regs.x86_32.cs_ar = 0xc9b;
+ hctxt->cpu_regs.x86_32.ds_base = 0;
+ hctxt->cpu_regs.x86_32.ds_limit = ~0u;
+ hctxt->cpu_regs.x86_32.ds_ar = 0xc93;
+ hctxt->cpu_regs.x86_32.es_base = 0;
+ hctxt->cpu_regs.x86_32.es_limit = ~0u;
+ hctxt->cpu_regs.x86_32.es_ar = 0xc93;
+ hctxt->cpu_regs.x86_32.ss_base = 0;
+ hctxt->cpu_regs.x86_32.ss_limit = ~0u;
+ hctxt->cpu_regs.x86_32.ss_ar = 0xc93;
+ hctxt->cpu_regs.x86_32.tr_base = 0;
+ hctxt->cpu_regs.x86_32.tr_limit = 0xff;
+ hctxt->cpu_regs.x86_32.tr_ar = 0x8b;
+#endif
+#endif
}

- if (HYPERVISOR_vcpu_op(VCPUOP_initialise, cpu, ctxt))
+ if (HYPERVISOR_vcpu_op(VCPUOP_initialise, cpu, ctxt_arg))
BUG();

- kfree(ctxt);
+ kfree(ctxt_arg);
return 0;
}

diff --git a/arch/x86/xen/smp.h b/arch/x86/xen/smp.h
index 963d62a..b4a833c 100644
--- a/arch/x86/xen/smp.h
+++ b/arch/x86/xen/smp.h
@@ -8,6 +8,10 @@ extern void xen_send_IPI_allbutself(int vector);
extern void xen_send_IPI_all(int vector);
extern void xen_send_IPI_self(int vector);

+#ifdef CONFIG_X86_32
+extern void hvmlite_smp_32(void);
+#endif
+
#ifdef CONFIG_XEN_PVH
extern void xen_pvh_early_cpu_init(int cpu, bool entry);
#else
diff --git a/arch/x86/xen/xen-hvmlite.S b/arch/x86/xen/xen-hvmlite.S
index 90f03d0..8d6a642 100644
--- a/arch/x86/xen/xen-hvmlite.S
+++ b/arch/x86/xen/xen-hvmlite.S
@@ -134,6 +134,13 @@ ENTRY(hvmlite_start_xen)
ljmp $0x10, $_pa(startup_32)
#endif

+#ifdef CONFIG_X86_32
+ENTRY(hvmlite_smp_32)
+ mov $_pa(boot_gdt_descr), %eax
+ lgdt (%eax)
+ jmp startup_32_smp
+#endif
+
.data
gdt:
.word gdt_end - gdt
--
1.7.1