[PATCH RFC v12 07/21] pvh: Disable unneeded features of HVM containers

[George Dunlap <george.dunlap@eu.citrix.com>]

Things kept:
* cacheattr_region lists
* irq-related structures
* paging
* tm_list

Things disabled for now:
* compat xlation

Things disabled:
* Emulated timers and clock sources
* IO/MMIO emulation
* msix tables
* hvm params
* hvm_funcs
* nested HVM
* Fast-path for emulated lapic accesses

Getting rid of the hvm_params struct required a couple other places to
check for its existence before attempting to read the params.

Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>
Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
CC: Jan Beulich <jan.beulich@suse.com>
CC: Tim Deegan <tim@xen.org>
CC: Keir Fraser <keir@xen.org>
---
 xen/arch/x86/hvm/hvm.c      |   37 ++++++++++++++++++++++++++++++++++---
 xen/arch/x86/hvm/io.c       |    4 ++++
 xen/arch/x86/hvm/irq.c      |    3 +++
 xen/arch/x86/hvm/mtrr.c     |    3 ++-
 xen/arch/x86/hvm/vmx/intr.c |    3 ++-
 xen/arch/x86/hvm/vmx/vmcs.c |    5 +++--
 xen/arch/x86/hvm/vmx/vmx.c  |   10 ++++++++--
 7 files changed, 56 insertions(+), 9 deletions(-)

diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 1764b78..6a7a006 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -301,6 +301,10 @@ u64 hvm_get_guest_tsc_adjust(struct vcpu *v)
 
 void hvm_migrate_timers(struct vcpu *v)
 {
+    /* PVH doesn't use rtc and emulated timers, it uses pvclock mechanism. */
+    if ( is_pvh_vcpu(v) )
+        return;
+
     rtc_migrate_timers(v);
     pt_migrate(v);
 }
@@ -342,10 +346,13 @@ void hvm_do_resume(struct vcpu *v)
 {
     ioreq_t *p;
 
-    pt_restore_timer(v);
-
     check_wakeup_from_wait();
 
+    if ( is_pvh_vcpu(v) )
+        goto check_inject_trap;
+
+    pt_restore_timer(v);
+
     /* NB. Optimised for common case (p->state == STATE_IOREQ_NONE). */
     p = get_ioreq(v);
     while ( p->state != STATE_IOREQ_NONE )
@@ -368,6 +375,7 @@ void hvm_do_resume(struct vcpu *v)
         }
     }
 
+  check_inject_trap:
     /* Inject pending hw/sw trap */
     if ( v->arch.hvm_vcpu.inject_trap.vector != -1 ) 
     {
@@ -521,6 +529,7 @@ int hvm_domain_initialise(struct domain *d)
         return -EINVAL;
     }
 
+    /* PVH: pbut_lock and uc_lock unused, but won't hurt */
     spin_lock_init(&d->arch.hvm_domain.pbuf_lock);
     spin_lock_init(&d->arch.hvm_domain.irq_lock);
     spin_lock_init(&d->arch.hvm_domain.uc_lock);
@@ -531,6 +540,9 @@ int hvm_domain_initialise(struct domain *d)
     if ( rc != 0 )
         goto fail0;
 
+    if ( is_pvh_domain(d) )
+        return 0;
+
     INIT_LIST_HEAD(&d->arch.hvm_domain.msixtbl_list);
     spin_lock_init(&d->arch.hvm_domain.msixtbl_list_lock);
 
@@ -584,6 +596,9 @@ int hvm_domain_initialise(struct domain *d)
 
 void hvm_domain_relinquish_resources(struct domain *d)
 {
+    if ( is_pvh_domain(d) )
+        return;
+
     if ( hvm_funcs.nhvm_domain_relinquish_resources )
         hvm_funcs.nhvm_domain_relinquish_resources(d);
 
@@ -609,6 +624,10 @@ void hvm_domain_relinquish_resources(struct domain *d)
 void hvm_domain_destroy(struct domain *d)
 {
     hvm_destroy_cacheattr_region_list(d);
+
+    if ( is_pvh_domain(d) )
+        return;
+
     hvm_funcs.domain_destroy(d);
     rtc_deinit(d);
     stdvga_deinit(d);
@@ -1093,6 +1112,14 @@ int hvm_vcpu_initialise(struct vcpu *v)
 
     v->arch.hvm_vcpu.inject_trap.vector = -1;
 
+    if ( is_pvh_vcpu(v) )
+    {
+        v->arch.hvm_vcpu.hcall_64bit = 1;    /* PVH 32bitfixme. */
+        /* This for hvm_long_mode_enabled(v). */
+        v->arch.hvm_vcpu.guest_efer = EFER_SCE | EFER_LMA | EFER_LME;
+        return 0;
+    }
+
     rc = setup_compat_arg_xlat(v); /* teardown: free_compat_arg_xlat() */
     if ( rc != 0 )
         goto fail3;
@@ -1168,7 +1195,10 @@ void hvm_vcpu_destroy(struct vcpu *v)
 
     tasklet_kill(&v->arch.hvm_vcpu.assert_evtchn_irq_tasklet);
     hvm_vcpu_cacheattr_destroy(v);
-    vlapic_destroy(v);
+
+    if ( is_hvm_vcpu(v) )
+        vlapic_destroy(v);
+
     hvm_funcs.vcpu_destroy(v);
 
     /* Event channel is already freed by evtchn_destroy(). */
@@ -1369,6 +1399,7 @@ int hvm_hap_nested_page_fault(paddr_t gpa,
     /* For the benefit of 32-bit WinXP (& older Windows) on AMD CPUs,
      * a fast path for LAPIC accesses, skipping the p2m lookup. */
     if ( !nestedhvm_vcpu_in_guestmode(v)
+         && is_hvm_vcpu(v)
          && gfn == PFN_DOWN(vlapic_base_address(vcpu_vlapic(v))) )
     {
         if ( !handle_mmio() )
diff --git a/xen/arch/x86/hvm/io.c b/xen/arch/x86/hvm/io.c
index 4ae2c0c..3af4b34 100644
--- a/xen/arch/x86/hvm/io.c
+++ b/xen/arch/x86/hvm/io.c
@@ -175,6 +175,10 @@ int handle_mmio(void)
     struct hvm_vcpu_io *vio = &curr->arch.hvm_vcpu.hvm_io;
     int rc;
 
+    /* No MMIO for PVH vcpus */
+    if ( is_pvh_vcpu(curr) )
+        return 0;
+
     hvm_emulate_prepare(&ctxt, guest_cpu_user_regs());
 
     rc = hvm_emulate_one(&ctxt);
diff --git a/xen/arch/x86/hvm/irq.c b/xen/arch/x86/hvm/irq.c
index 9eae5de..92fb245 100644
--- a/xen/arch/x86/hvm/irq.c
+++ b/xen/arch/x86/hvm/irq.c
@@ -405,6 +405,9 @@ struct hvm_intack hvm_vcpu_has_pending_irq(struct vcpu *v)
          && vcpu_info(v, evtchn_upcall_pending) )
         return hvm_intack_vector(plat->irq.callback_via.vector);
 
+    if ( is_pvh_vcpu(v) )
+        return hvm_intack_none;
+
     if ( vlapic_accept_pic_intr(v) && plat->vpic[0].int_output )
         return hvm_intack_pic(0);
 
diff --git a/xen/arch/x86/hvm/mtrr.c b/xen/arch/x86/hvm/mtrr.c
index ef51a8d..df888a6 100644
--- a/xen/arch/x86/hvm/mtrr.c
+++ b/xen/arch/x86/hvm/mtrr.c
@@ -693,7 +693,8 @@ uint8_t epte_get_entry_emt(struct domain *d, unsigned long gfn, mfn_t mfn,
          ((d->vcpu == NULL) || ((v = d->vcpu[0]) == NULL)) )
         return MTRR_TYPE_WRBACK;
 
-    if ( !v->domain->arch.hvm_domain.params[HVM_PARAM_IDENT_PT] )
+    if ( v->domain->arch.hvm_domain.params
+         && !v->domain->arch.hvm_domain.params[HVM_PARAM_IDENT_PT] )
         return MTRR_TYPE_WRBACK;
 
     if ( (v == current) && v->domain->arch.hvm_domain.is_in_uc_mode )
diff --git a/xen/arch/x86/hvm/vmx/intr.c b/xen/arch/x86/hvm/vmx/intr.c
index e376f3c..5a7a62e 100644
--- a/xen/arch/x86/hvm/vmx/intr.c
+++ b/xen/arch/x86/hvm/vmx/intr.c
@@ -220,7 +220,8 @@ void vmx_intr_assist(void)
     }
 
     /* Crank the handle on interrupt state. */
-    pt_vector = pt_update_irq(v);
+    if ( is_hvm_vcpu(v) )
+        pt_vector = pt_update_irq(v);
 
     do {
         intack = hvm_vcpu_has_pending_irq(v);
diff --git a/xen/arch/x86/hvm/vmx/vmcs.c b/xen/arch/x86/hvm/vmx/vmcs.c
index 7087630..fa90493 100644
--- a/xen/arch/x86/hvm/vmx/vmcs.c
+++ b/xen/arch/x86/hvm/vmx/vmcs.c
@@ -1295,8 +1295,9 @@ void vmx_do_resume(struct vcpu *v)
     }
 
     debug_state = v->domain->debugger_attached
-                  || v->domain->arch.hvm_domain.params[HVM_PARAM_MEMORY_EVENT_INT3]
-                  || v->domain->arch.hvm_domain.params[HVM_PARAM_MEMORY_EVENT_SINGLE_STEP];
+                  || (v->domain->arch.hvm_domain.params
+                      && (v->domain->arch.hvm_domain.params[HVM_PARAM_MEMORY_EVENT_INT3]
+                          || v->domain->arch.hvm_domain.params[HVM_PARAM_MEMORY_EVENT_SINGLE_STEP]));
 
     if ( unlikely(v->arch.hvm_vcpu.debug_state_latch != debug_state) )
     {
diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c
index f02e47a..0ac96ab 100644
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -788,7 +788,8 @@ static void vmx_set_segment_register(struct vcpu *v, enum x86_segment seg,
         
         if ( seg == x86_seg_tr ) 
         {
-            if ( v->domain->arch.hvm_domain.params[HVM_PARAM_VM86_TSS] )
+            if ( v->domain->arch.hvm_domain.params
+                 && v->domain->arch.hvm_domain.params[HVM_PARAM_VM86_TSS] )
             {
                 sel = 0;
                 attr = vm86_tr_attr;
@@ -1078,7 +1079,8 @@ static void vmx_update_guest_cr(struct vcpu *v, unsigned int cr)
                 v->arch.hvm_vmx.exec_control |= cr3_ctls;
 
             /* Trap CR3 updates if CR3 memory events are enabled. */
-            if ( v->domain->arch.hvm_domain.params[HVM_PARAM_MEMORY_EVENT_CR3] )
+            if ( v->domain->arch.hvm_domain.params
+                 && v->domain->arch.hvm_domain.params[HVM_PARAM_MEMORY_EVENT_CR3] )
                 v->arch.hvm_vmx.exec_control |= CPU_BASED_CR3_LOAD_EXITING;
 
             vmx_update_cpu_exec_control(v);
@@ -1145,8 +1147,12 @@ static void vmx_update_guest_cr(struct vcpu *v, unsigned int cr)
         if ( paging_mode_hap(v->domain) )
         {
             if ( !hvm_paging_enabled(v) )
+            {
+                /* We should never get here for pvh domains */
+                ASSERT(v->domain->arch.hvm_domain.params);
                 v->arch.hvm_vcpu.hw_cr[3] =
                     v->domain->arch.hvm_domain.params[HVM_PARAM_IDENT_PT];
+            }
             vmx_load_pdptrs(v);
         }
  
-- 
1.7.9.5