[PATCH 09/18] PVH xen: domain creation code changes

[Mukesh Rathor <mukesh.rathor@oracle.com>]

This patch contains changes to arch/x86/domain.c to allow for a PVH
domain.
Changes in V2:
  - changes to read_segment_register() moved to this patch.
  - The other comment was to create NULL functions for pvh_set_vcpu_info
    and pvh_read_descriptor which are implemented in later patch, but since
    I disable PVH creation until all patches are checked in, it is not needed.
    But it helps breaking down of patches.

Changes in V3:
  - Fix read_segment_register() macro to make sure args are evaluated once,
    and use # instead of STR for name in the macro.

Changes in V4:
  - Remove pvh substruct in the hvm substruct, as the vcpu_info_mfn has been
    moved out of pv_vcpu struct.
  - rename hvm_pvh_* functions to hvm_*.

Changes in V5:
  - remove pvh_read_descriptor().

Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
---
 xen/arch/x86/domain.c         |   61 +++++++++++++++++++++++++++-------------
 xen/arch/x86/mm.c             |    3 ++
 xen/arch/x86/mm/hap/hap.c     |    4 ++-
 xen/include/asm-x86/hvm/hvm.h |    8 +++++
 xen/include/asm-x86/system.h  |   18 +++++++++---
 5 files changed, 69 insertions(+), 25 deletions(-)

diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index 31a8a50..9953f80 100644
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -385,7 +385,7 @@ int vcpu_initialise(struct vcpu *v)
 
     vmce_init_vcpu(v);
 
-    if ( is_hvm_domain(d) )
+    if ( !is_pv_domain(d) )
     {
         rc = hvm_vcpu_initialise(v);
         goto done;
@@ -452,7 +452,7 @@ void vcpu_destroy(struct vcpu *v)
 
     vcpu_destroy_fpu(v);
 
-    if ( is_hvm_vcpu(v) )
+    if ( !is_pv_vcpu(v) )
         hvm_vcpu_destroy(v);
     else
         xfree(v->arch.pv_vcpu.trap_ctxt);
@@ -464,7 +464,7 @@ int arch_domain_create(struct domain *d, unsigned int domcr_flags)
     int rc = -ENOMEM;
 
     d->arch.hvm_domain.hap_enabled =
-        is_hvm_domain(d) &&
+        !is_pv_domain(d) &&
         hvm_funcs.hap_supported &&
         (domcr_flags & DOMCRF_hap);
     d->arch.hvm_domain.mem_sharing_enabled = 0;
@@ -512,7 +512,7 @@ int arch_domain_create(struct domain *d, unsigned int domcr_flags)
     mapcache_domain_init(d);
 
     HYPERVISOR_COMPAT_VIRT_START(d) =
-        is_hvm_domain(d) ? ~0u : __HYPERVISOR_COMPAT_VIRT_START;
+        is_pv_domain(d) ? __HYPERVISOR_COMPAT_VIRT_START : ~0u;
 
     if ( (rc = paging_domain_init(d, domcr_flags)) != 0 )
         goto fail;
@@ -555,7 +555,7 @@ int arch_domain_create(struct domain *d, unsigned int domcr_flags)
     }
     spin_lock_init(&d->arch.e820_lock);
 
-    if ( is_hvm_domain(d) )
+    if ( !is_pv_domain(d) )
     {
         if ( (rc = hvm_domain_initialise(d)) != 0 )
         {
@@ -658,7 +658,7 @@ int arch_set_info_guest(
 #define c(fld) (compat ? (c.cmp->fld) : (c.nat->fld))
     flags = c(flags);
 
-    if ( !is_hvm_vcpu(v) )
+    if ( is_pv_vcpu(v) )
     {
         if ( !compat )
         {
@@ -711,7 +711,7 @@ int arch_set_info_guest(
     v->fpu_initialised = !!(flags & VGCF_I387_VALID);
 
     v->arch.flags &= ~TF_kernel_mode;
-    if ( (flags & VGCF_in_kernel) || is_hvm_vcpu(v)/*???*/ )
+    if ( (flags & VGCF_in_kernel) || !is_pv_vcpu(v)/*???*/ )
         v->arch.flags |= TF_kernel_mode;
 
     v->arch.vgc_flags = flags;
@@ -722,7 +722,7 @@ int arch_set_info_guest(
     if ( !compat )
     {
         memcpy(&v->arch.user_regs, &c.nat->user_regs, sizeof(c.nat->user_regs));
-        if ( !is_hvm_vcpu(v) )
+        if ( is_pv_vcpu(v) )
             memcpy(v->arch.pv_vcpu.trap_ctxt, c.nat->trap_ctxt,
                    sizeof(c.nat->trap_ctxt));
     }
@@ -738,10 +738,13 @@ int arch_set_info_guest(
 
     v->arch.user_regs.eflags |= 2;
 
-    if ( is_hvm_vcpu(v) )
+    if ( !is_pv_vcpu(v) )
     {
         hvm_set_info_guest(v);
-        goto out;
+        if ( is_hvm_vcpu(v) || v->is_initialised )
+            goto out;
+        else
+            goto pvh_skip_pv_stuff;
     }
 
     init_int80_direct_trap(v);
@@ -750,7 +753,10 @@ int arch_set_info_guest(
     v->arch.pv_vcpu.iopl = (v->arch.user_regs.eflags >> 12) & 3;
     v->arch.user_regs.eflags &= ~X86_EFLAGS_IOPL;
 
-    /* Ensure real hardware interrupts are enabled. */
+    /*
+     * Ensure real hardware interrupts are enabled. Note: PVH may not have
+     * IDT set on all vcpus so we don't enable IF for it yet.
+     */
     v->arch.user_regs.eflags |= X86_EFLAGS_IF;
 
     if ( !v->is_initialised )
@@ -852,6 +858,7 @@ int arch_set_info_guest(
 
     set_bit(_VPF_in_reset, &v->pause_flags);
 
+pvh_skip_pv_stuff:
     if ( !compat )
         cr3_gfn = xen_cr3_to_pfn(c.nat->ctrlreg[3]);
     else
@@ -860,7 +867,7 @@ int arch_set_info_guest(
 
     if ( !cr3_page )
         rc = -EINVAL;
-    else if ( paging_mode_refcounts(d) )
+    else if ( paging_mode_refcounts(d) || is_pvh_vcpu(v) )
         /* nothing */;
     else if ( cr3_page == v->arch.old_guest_table )
     {
@@ -886,8 +893,15 @@ int arch_set_info_guest(
         /* handled below */;
     else if ( !compat )
     {
+        /* PVH 32bitfixme */
+        if ( is_pvh_vcpu(v) )
+        {
+            v->arch.cr3 = page_to_mfn(cr3_page);
+            v->arch.hvm_vcpu.guest_cr[3] = c.nat->ctrlreg[3];
+        }
+
         v->arch.guest_table = pagetable_from_page(cr3_page);
-        if ( c.nat->ctrlreg[1] )
+        if ( c.nat->ctrlreg[1] && !is_pvh_vcpu(v) )
         {
             cr3_gfn = xen_cr3_to_pfn(c.nat->ctrlreg[1]);
             cr3_page = get_page_from_gfn(d, cr3_gfn, NULL, P2M_ALLOC);
@@ -942,6 +956,13 @@ int arch_set_info_guest(
 
     update_cr3(v);
 
+    if ( is_pvh_vcpu(v) )
+    {
+        /* guest is bringing up non-boot SMP vcpu */
+        if ( (rc=hvm_set_vcpu_info(v, c.nat)) != 0 )
+            return rc;
+    }
+
  out:
     if ( flags & VGCF_online )
         clear_bit(_VPF_down, &v->pause_flags);
@@ -1309,7 +1330,7 @@ static void update_runstate_area(struct vcpu *v)
 
 static inline int need_full_gdt(struct vcpu *v)
 {
-    return (!is_hvm_vcpu(v) && !is_idle_vcpu(v));
+    return (is_pv_vcpu(v) && !is_idle_vcpu(v));
 }
 
 static void __context_switch(void)
@@ -1443,7 +1464,7 @@ void context_switch(struct vcpu *prev, struct vcpu *next)
         /* Re-enable interrupts before restoring state which may fault. */
         local_irq_enable();
 
-        if ( !is_hvm_vcpu(next) )
+        if ( is_pv_vcpu(next) )
         {
             load_LDT(next);
             load_segments(next);
@@ -1566,12 +1587,12 @@ unsigned long hypercall_create_continuation(
         regs->eax  = op;
 
         /* Ensure the hypercall trap instruction is re-executed. */
-        if ( !is_hvm_vcpu(current) )
+        if ( is_pv_vcpu(current) )
             regs->eip -= 2;  /* re-execute 'syscall' / 'int $xx' */
         else
             current->arch.hvm_vcpu.hcall_preempted = 1;
 
-        if ( !is_hvm_vcpu(current) ?
+        if ( is_pv_vcpu(current) ?
              !is_pv_32on64_vcpu(current) :
              (hvm_guest_x86_mode(current) == 8) )
         {
@@ -1839,7 +1860,7 @@ int domain_relinquish_resources(struct domain *d)
                 return ret;
         }
 
-        if ( !is_hvm_domain(d) )
+        if ( is_pv_domain(d) )
         {
             for_each_vcpu ( d, v )
             {
@@ -1912,7 +1933,7 @@ int domain_relinquish_resources(struct domain *d)
         BUG();
     }
 
-    if ( is_hvm_domain(d) )
+    if ( !is_pv_domain(d) )
         hvm_domain_relinquish_resources(d);
 
     return 0;
@@ -1996,7 +2017,7 @@ void vcpu_mark_events_pending(struct vcpu *v)
     if ( already_pending )
         return;
 
-    if ( is_hvm_vcpu(v) )
+    if ( !is_pv_vcpu(v) )
         hvm_assert_evtchn_irq(v);
     else
         vcpu_kick(v);
diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index bd1402e..b190ad9 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -4330,6 +4330,9 @@ void destroy_gdt(struct vcpu *v)
     int i;
     unsigned long pfn;
 
+    if ( is_pvh_vcpu(v) )
+        return;
+
     v->arch.pv_vcpu.gdt_ents = 0;
     pl1e = gdt_ldt_ptes(v->domain, v);
     for ( i = 0; i < FIRST_RESERVED_GDT_PAGE; i++ )
diff --git a/xen/arch/x86/mm/hap/hap.c b/xen/arch/x86/mm/hap/hap.c
index bff05d9..5aa0852 100644
--- a/xen/arch/x86/mm/hap/hap.c
+++ b/xen/arch/x86/mm/hap/hap.c
@@ -639,7 +639,9 @@ static void hap_update_cr3(struct vcpu *v, int do_locking)
 const struct paging_mode *
 hap_paging_get_mode(struct vcpu *v)
 {
-    return !hvm_paging_enabled(v)   ? &hap_paging_real_mode :
+    /* PVH 32bitfixme */
+    return is_pvh_vcpu(v) ? &hap_paging_long_mode :
+        !hvm_paging_enabled(v)   ? &hap_paging_real_mode :
         hvm_long_mode_enabled(v) ? &hap_paging_long_mode :
         hvm_pae_enabled(v)       ? &hap_paging_pae_mode  :
                                    &hap_paging_protected_mode;
diff --git a/xen/include/asm-x86/hvm/hvm.h b/xen/include/asm-x86/hvm/hvm.h
index 8408420..7e21ee1 100644
--- a/xen/include/asm-x86/hvm/hvm.h
+++ b/xen/include/asm-x86/hvm/hvm.h
@@ -192,6 +192,8 @@ struct hvm_function_table {
                                 paddr_t *L1_gpa, unsigned int *page_order,
                                 uint8_t *p2m_acc, bool_t access_r,
                                 bool_t access_w, bool_t access_x);
+    /* PVH functions */
+    int (*pvh_set_vcpu_info)(struct vcpu *v, struct vcpu_guest_context *ctxtp);
 };
 
 extern struct hvm_function_table hvm_funcs;
@@ -325,6 +327,12 @@ static inline unsigned long hvm_get_shadow_gs_base(struct vcpu *v)
     return hvm_funcs.get_shadow_gs_base(v);
 }
 
+static inline int hvm_set_vcpu_info(struct vcpu *v,
+                                        struct vcpu_guest_context *ctxtp)
+{
+    return hvm_funcs.pvh_set_vcpu_info(v, ctxtp);
+}
+
 #define is_viridian_domain(_d)                                             \
  (is_hvm_domain(_d) && ((_d)->arch.hvm_domain.params[HVM_PARAM_VIRIDIAN]))
 
diff --git a/xen/include/asm-x86/system.h b/xen/include/asm-x86/system.h
index 9bb22cb..955983b 100644
--- a/xen/include/asm-x86/system.h
+++ b/xen/include/asm-x86/system.h
@@ -4,10 +4,20 @@
 #include <xen/lib.h>
 #include <xen/bitops.h>
 
-#define read_segment_register(vcpu, regs, name)                 \
-({  u16 __sel;                                                  \
-    asm volatile ( "movw %%" STR(name) ",%0" : "=r" (__sel) );  \
-    __sel;                                                      \
+/*
+ * We need vcpu because during context switch, going from pure PV to PVH,
+ * in save_segments(), current has been updated to next, and no longer pointing
+ * to the pure PV. Note: for PVH, we update regs->selectors on each vmexit.
+ */
+#define read_segment_register(vcpu, regs, name)                   \
+({  u16 __sel;                                                    \
+    struct cpu_user_regs *_regs = (regs);                         \
+                                                                  \
+    if ( is_pvh_vcpu(vcpu) )                                      \
+        __sel = _regs->name;                                      \
+    else                                                          \
+        asm volatile ( "movw %%" #name ",%0" : "=r" (__sel) );    \
+    __sel;                                                        \
 })
 
 #define wbinvd() \
-- 
1.7.2.3