[PATCH 10/18 V2]: PVH xen: introduce vmx_pvh.c and pvh.c

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

The heart of this patch is vmx exit handler for PVH guest. It is nicely
 isolated in a separate module as preferred by most of us. A call to it
 is added to vmx_pvh_vmexit_handler().

Changes in V2:
  - Move non VMX generic code to arch/x86/hvm/pvh.c
  - Remove get_gpr_ptr() and use existing decode_register() instead.
  - Defer call to pvh vmx exit handler until interrupts are enabled. So the
    caller vmx_pvh_vmexit_handler() handles the NMI/EXT-INT/TRIPLE_FAULT now.
  - Fix the CPUID (wrongly) clearing bit 24. No need to do this now, set
    the correct feature bits in CR4 during vmcs creation.
  - Fix few hard tabs.

Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
---
 xen/arch/x86/hvm/Makefile         |    3 +-
 xen/arch/x86/hvm/pvh.c            |  220 ++++++++++++++
 xen/arch/x86/hvm/vmx/Makefile     |    1 +
 xen/arch/x86/hvm/vmx/vmx.c        |    7 +
 xen/arch/x86/hvm/vmx/vmx_pvh.c    |  587 +++++++++++++++++++++++++++++++++++++
 xen/include/asm-x86/hvm/vmx/vmx.h |    7 +-
 xen/include/asm-x86/pvh.h         |    6 +
 7 files changed, 829 insertions(+), 2 deletions(-)
 create mode 100644 xen/arch/x86/hvm/pvh.c
 create mode 100644 xen/arch/x86/hvm/vmx/vmx_pvh.c
 create mode 100644 xen/include/asm-x86/pvh.h

diff --git a/xen/arch/x86/hvm/Makefile b/xen/arch/x86/hvm/Makefile
index eea5555..65ff9f3 100644
--- a/xen/arch/x86/hvm/Makefile
+++ b/xen/arch/x86/hvm/Makefile
@@ -22,4 +22,5 @@ obj-y += vlapic.o
 obj-y += vmsi.o
 obj-y += vpic.o
 obj-y += vpt.o
-obj-y += vpmu.o
\ No newline at end of file
+obj-y += vpmu.o
+obj-y += pvh.o
diff --git a/xen/arch/x86/hvm/pvh.c b/xen/arch/x86/hvm/pvh.c
new file mode 100644
index 0000000..c12c4b7
--- /dev/null
+++ b/xen/arch/x86/hvm/pvh.c
@@ -0,0 +1,220 @@
+/*
+ * Copyright (C) 2013, Mukesh Rathor, Oracle Corp.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <xen/hypercall.h>
+#include <xen/guest_access.h>
+#include <asm/p2m.h>
+#include <asm/traps.h>
+#include <asm/hvm/vmx/vmx.h>
+#include <public/sched.h>
+
+static int pvh_grant_table_op(
+              unsigned int cmd, XEN_GUEST_HANDLE(void) uop, unsigned int count)
+{
+    switch (cmd)
+    {
+        case GNTTABOP_map_grant_ref:
+        case GNTTABOP_unmap_grant_ref:
+        case GNTTABOP_setup_table:
+        case GNTTABOP_copy:
+        case GNTTABOP_query_size:
+        case GNTTABOP_set_version:
+            return do_grant_table_op(cmd, uop, count);
+    }
+    return -ENOSYS;
+}
+
+static long pvh_vcpu_op(int cmd, int vcpuid, XEN_GUEST_HANDLE(void) arg)
+{
+    long rc = -ENOSYS;
+
+    switch ( cmd )
+    {
+        case VCPUOP_register_runstate_memory_area:
+        case VCPUOP_get_runstate_info:
+        case VCPUOP_set_periodic_timer:
+        case VCPUOP_stop_periodic_timer:
+        case VCPUOP_set_singleshot_timer:
+        case VCPUOP_stop_singleshot_timer:
+        case VCPUOP_is_up:
+        case VCPUOP_up:
+        case VCPUOP_initialise:
+            rc = do_vcpu_op(cmd, vcpuid, arg);
+
+            /* pvh boot vcpu setting context for bringing up smp vcpu */
+            if (cmd == VCPUOP_initialise)
+                vmx_vmcs_enter(current);
+    }
+    return rc;
+}
+
+static long pvh_physdev_op(int cmd, XEN_GUEST_HANDLE(void) arg)
+{
+    switch ( cmd )
+    {
+        case PHYSDEVOP_map_pirq:
+        case PHYSDEVOP_unmap_pirq:
+        case PHYSDEVOP_eoi:
+        case PHYSDEVOP_irq_status_query:
+        case PHYSDEVOP_get_free_pirq:
+            return do_physdev_op(cmd, arg);
+
+        default:
+            if ( IS_PRIV(current->domain) )
+                return do_physdev_op(cmd, arg);
+    }
+    return -ENOSYS;
+}
+
+static long do_pvh_hvm_op(unsigned long op, XEN_GUEST_HANDLE(void) arg)
+{
+    long rc = -EINVAL;
+    struct xen_hvm_param harg;
+    struct domain *d;
+
+    if ( copy_from_guest(&harg, arg, 1) )
+        return -EFAULT;
+
+    rc = rcu_lock_target_domain_by_id(harg.domid, &d);
+    if ( rc != 0 )
+        return rc;
+
+    if (is_hvm_domain(d)) {
+        /* pvh dom0 is building an hvm guest */
+        rcu_unlock_domain(d);
+        return do_hvm_op(op, arg);  
+    }
+
+    rc = -ENOSYS;
+    if (op == HVMOP_set_param) {
+        if (harg.index == HVM_PARAM_CALLBACK_IRQ) {
+            struct hvm_irq *hvm_irq = &d->arch.hvm_domain.irq;
+            uint64_t via = harg.value;
+            uint8_t via_type = (uint8_t)(via >> 56) + 1;
+
+            if (via_type == HVMIRQ_callback_vector) {
+                hvm_irq->callback_via_type = HVMIRQ_callback_vector;
+                hvm_irq->callback_via.vector = (uint8_t)via;
+                rc = 0;
+            }
+        }
+    }
+    rcu_unlock_domain(d);
+    return rc;
+}
+
+typedef unsigned long pvh_hypercall_t(
+    unsigned long, unsigned long, unsigned long, unsigned long, unsigned long,
+    unsigned long);
+
+int hcall_a[NR_hypercalls];
+
+static pvh_hypercall_t *pvh_hypercall64_table[NR_hypercalls] = {
+    [__HYPERVISOR_platform_op]     = (pvh_hypercall_t *)do_platform_op,
+    [__HYPERVISOR_memory_op]       = (pvh_hypercall_t *)do_memory_op,
+    /* [__HYPERVISOR_set_timer_op]     = (pvh_hypercall_t *)do_set_timer_op, */
+    [__HYPERVISOR_xen_version]     = (pvh_hypercall_t *)do_xen_version,
+    [__HYPERVISOR_console_io]      = (pvh_hypercall_t *)do_console_io,
+    [__HYPERVISOR_grant_table_op]  = (pvh_hypercall_t *)pvh_grant_table_op,
+    [__HYPERVISOR_vcpu_op]         = (pvh_hypercall_t *)pvh_vcpu_op,
+    [__HYPERVISOR_mmuext_op]       = (pvh_hypercall_t *)do_mmuext_op,
+    [__HYPERVISOR_xsm_op]          = (pvh_hypercall_t *)do_xsm_op,
+    [__HYPERVISOR_sched_op]        = (pvh_hypercall_t *)do_sched_op,
+    [__HYPERVISOR_event_channel_op]= (pvh_hypercall_t *)do_event_channel_op,
+    [__HYPERVISOR_physdev_op]      = (pvh_hypercall_t *)pvh_physdev_op,
+    [__HYPERVISOR_hvm_op]          = (pvh_hypercall_t *)do_pvh_hvm_op,
+    [__HYPERVISOR_sysctl]          = (pvh_hypercall_t *)do_sysctl,
+    [__HYPERVISOR_domctl]          = (pvh_hypercall_t *)do_domctl
+};
+
+/* fixme: Do we need to worry about this and slow things down in this path? */
+static int pvh_long_mode_enabled(void)
+{
+    /* A 64bit linux guest should always run in this mode with CS.L selecting
+     * either 64bit mode or 32bit compat mode */
+    return 1;
+}
+
+/* Check if hypercall is valid 
+ * Returns: 0 if hcall is not valid with eax set to the errno to ret to guest
+ */
+static int hcall_valid(struct cpu_user_regs *regs)
+{
+    struct segment_register sreg;
+
+    if (!pvh_long_mode_enabled()) 
+    {
+        gdprintk(XENLOG_ERR, "PVH Error: Expected long mode set\n");
+        return 1;
+    }
+    hvm_get_segment_register(current, x86_seg_ss, &sreg);
+    if ( unlikely(sreg.attr.fields.dpl == 3) ) 
+    {
+        regs->eax = -EPERM;
+        return 0;
+    }
+
+    /* domU's are not allowed following hcalls */
+    if ( !IS_PRIV(current->domain) &&
+         (regs->eax == __HYPERVISOR_xsm_op ||
+          regs->eax == __HYPERVISOR_platform_op ||
+          regs->eax == __HYPERVISOR_domctl) ) {     /* for privcmd mmap */
+
+        regs->eax = -EPERM;
+        return 0;
+    }
+    return 1;
+}
+
+int pvh_do_hypercall(struct cpu_user_regs *regs)
+{
+    uint32_t hnum = regs->eax;
+
+    if ( hnum >= NR_hypercalls || pvh_hypercall64_table[hnum] == NULL ) 
+    {
+        gdprintk(XENLOG_WARNING, "PVH: Unimplemented HCALL:%d. Returning " 
+                 "-ENOSYS. domid:%d IP:%lx SP:%lx\n", 
+                 hnum, current->domain->domain_id, regs->rip, regs->rsp);
+        regs->eax = -ENOSYS;
+        vmx_update_guest_eip();
+        return HVM_HCALL_completed;
+    }
+
+    if ( regs->eax == __HYPERVISOR_sched_op && regs->rdi == SCHEDOP_shutdown ) 
+    {
+        regs->eax = -ENOSYS;
+        vmx_update_guest_eip();
+
+        /* PVH fixme: show_guest_stack() from domain crash causes PF */
+        domain_crash_synchronous();
+        return HVM_HCALL_completed;
+    }
+
+    if ( !hcall_valid(regs) )
+        return HVM_HCALL_completed;
+
+    current->arch.hvm_vcpu.hcall_preempted = 0;
+    regs->rax = pvh_hypercall64_table[hnum](regs->rdi, regs->rsi, regs->rdx,
+                                            regs->r10, regs->r8, regs->r9);
+
+    if ( current->arch.hvm_vcpu.hcall_preempted )
+        return HVM_HCALL_preempted;
+         
+    return HVM_HCALL_completed;
+}
+
diff --git a/xen/arch/x86/hvm/vmx/Makefile b/xen/arch/x86/hvm/vmx/Makefile
index 373b3d9..8b71dae 100644
--- a/xen/arch/x86/hvm/vmx/Makefile
+++ b/xen/arch/x86/hvm/vmx/Makefile
@@ -5,3 +5,4 @@ obj-y += vmcs.o
 obj-y += vmx.o
 obj-y += vpmu_core2.o
 obj-y += vvmx.o
+obj-y += vmx_pvh.o
diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c
index 194c87b..5503fc9 100644
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -1529,6 +1529,8 @@ static struct hvm_function_table __read_mostly vmx_function_table = {
     .virtual_intr_delivery_enabled = vmx_virtual_intr_delivery_enabled,
     .process_isr          = vmx_process_isr,
     .nhvm_hap_walk_L1_p2m = nvmx_hap_walk_L1_p2m,
+    .pvh_set_vcpu_info    = vmx_pvh_set_vcpu_info,
+    .pvh_read_descriptor  = vmx_pvh_read_descriptor,
 };
 
 struct hvm_function_table * __init start_vmx(void)
@@ -2364,6 +2366,11 @@ void vmx_vmexit_handler(struct cpu_user_regs *regs)
     if ( unlikely(exit_reason & VMX_EXIT_REASONS_FAILED_VMENTRY) )
         return vmx_failed_vmentry(exit_reason, regs);
 
+    if ( is_pvh_vcpu(v) ) {
+        vmx_pvh_vmexit_handler(regs);
+        return;
+    }
+
     if ( v->arch.hvm_vmx.vmx_realmode )
     {
         /* Put RFLAGS back the way the guest wants it */
diff --git a/xen/arch/x86/hvm/vmx/vmx_pvh.c b/xen/arch/x86/hvm/vmx/vmx_pvh.c
new file mode 100644
index 0000000..14ca0f6
--- /dev/null
+++ b/xen/arch/x86/hvm/vmx/vmx_pvh.c
@@ -0,0 +1,587 @@
+/*
+ * Copyright (C) 2013, Mukesh Rathor, Oracle Corp.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <xen/hypercall.h>
+#include <xen/guest_access.h>
+#include <asm/p2m.h>
+#include <asm/traps.h>
+#include <asm/hvm/vmx/vmx.h>
+#include <public/sched.h>
+#include <asm/pvh.h>
+
+volatile int pvhdbg=0;
+#define dbgp1(...) {(pvhdbg==1) ? printk(__VA_ARGS__):0;}
+#define dbgp2(...) {(pvhdbg==2) ? printk(__VA_ARGS__):0;}
+
+
+static void read_vmcs_selectors(struct cpu_user_regs *regs)
+{
+    regs->cs = __vmread(GUEST_CS_SELECTOR);
+    regs->ss = __vmread(GUEST_SS_SELECTOR);
+    regs->ds = __vmread(GUEST_DS_SELECTOR);
+    regs->es = __vmread(GUEST_ES_SELECTOR);
+    regs->gs = __vmread(GUEST_GS_SELECTOR);
+    regs->fs = __vmread(GUEST_FS_SELECTOR);
+}
+
+/* returns : 0 success */
+static int vmxit_msr_read(struct cpu_user_regs *regs)
+{
+    int rc=1;
+
+    u64 msr_content = 0;
+    switch (regs->ecx)
+    {
+        case MSR_IA32_MISC_ENABLE:
+        {
+            rdmsrl(MSR_IA32_MISC_ENABLE, msr_content);
+            msr_content |= MSR_IA32_MISC_ENABLE_BTS_UNAVAIL |
+                           MSR_IA32_MISC_ENABLE_PEBS_UNAVAIL;
+            break;
+        }
+        default:
+        {
+            /* fixme: see hvm_msr_read_intercept() */
+            rdmsrl(regs->ecx, msr_content);  
+            break;
+        }
+    }
+    regs->eax = (uint32_t)msr_content;
+    regs->edx = (uint32_t)(msr_content >> 32);
+    vmx_update_guest_eip();
+    rc = 0;
+
+    dbgp1("msr read c:%lx a:%lx d:%lx RIP:%lx RSP:%lx\n", regs->ecx, regs->eax, 
+          regs->edx, regs->rip, regs->rsp);
+    return rc;
+}
+
+/* returns : 0 success */
+static int vmxit_msr_write(struct cpu_user_regs *regs)
+{
+    uint64_t msr_content = (uint32_t)regs->eax | ((uint64_t)regs->edx << 32);
+    int rc=1;
+
+    dbgp1("PVH: msr write:0x%lx. eax:0x%lx edx:0x%lx\n", regs->ecx, 
+          regs->eax,regs->edx);
+
+    if ( hvm_msr_write_intercept(regs->ecx, msr_content) == X86EMUL_OKAY ) {
+        vmx_update_guest_eip();
+        rc = 0;
+    }
+    return rc;
+}
+
+/* Returns: rc == 0: handled the MTF vmexit */
+static int vmxit_mtf(struct cpu_user_regs *regs)
+{
+    struct vcpu *vp = current;
+    int rc=1, ss=vp->arch.hvm_vcpu.single_step; 
+
+    vp->arch.hvm_vmx.exec_control &= ~CPU_BASED_MONITOR_TRAP_FLAG;
+    __vmwrite(CPU_BASED_VM_EXEC_CONTROL, vp->arch.hvm_vmx.exec_control);
+    vp->arch.hvm_vcpu.single_step = 0;
+
+    if ( vp->domain->debugger_attached && ss ) {
+        domain_pause_for_debugger();
+        rc = 0;
+    }
+    return rc;
+}
+
+static int vmxit_int3(struct cpu_user_regs *regs)
+{
+    int ilen = vmx_get_instruction_length();
+    struct vcpu *vp = current;
+    struct hvm_trap trap_info = { 
+                        .vector = TRAP_int3, 
+                        .type = X86_EVENTTYPE_SW_EXCEPTION,
+                        .error_code = HVM_DELIVER_NO_ERROR_CODE, 
+                        .insn_len = ilen
+    };
+
+    regs->eip += ilen;
+
+    /* gdbsx or another debugger. Never pause dom0 */
+    if ( vp->domain->domain_id != 0 && guest_kernel_mode(vp, regs) )
+    {
+        dbgp1("[%d]PVH: domain pause for debugger\n", smp_processor_id());
+        current->arch.gdbsx_vcpu_event = TRAP_int3;
+        domain_pause_for_debugger();
+        return 0;
+    }
+
+    regs->eip -= ilen;
+    hvm_inject_trap(&trap_info);
+
+    return 0;
+}
+
+static int vmxit_invalid_op(struct cpu_user_regs *regs)
+{
+    ulong addr=0;
+
+    if ( guest_kernel_mode(current, regs) || 
+         (addr = emulate_forced_invalid_op(regs)) == 0 )
+    {
+        hvm_inject_hw_exception(TRAP_invalid_op, HVM_DELIVER_NO_ERROR_CODE);
+        return 0;
+    } 
+
+    if (addr != EXCRET_fault_fixed)
+        hvm_inject_page_fault(0, addr);
+
+    return 0;
+}
+
+/* Returns: rc == 0: handled the exception/NMI */
+static int vmxit_exception(struct cpu_user_regs *regs)
+{
+    unsigned int vector = (__vmread(VM_EXIT_INTR_INFO)) & INTR_INFO_VECTOR_MASK;
+    int rc=1; 
+    struct vcpu *vp = current;
+
+    dbgp2(" EXCPT: vec:%d cs:%lx r.IP:%lx\n", vector, 
+          __vmread(GUEST_CS_SELECTOR), regs->eip);
+
+    if (vector == TRAP_debug) {
+        unsigned long exit_qualification = __vmread(EXIT_QUALIFICATION);
+        write_debugreg(6, exit_qualification | 0xffff0ff0);
+        rc = 0;
+        
+        /* gdbsx or another debugger */
+        if ( vp->domain->domain_id != 0 &&    /* never pause dom0 */
+             guest_kernel_mode(vp, regs) &&  vp->domain->debugger_attached )
+        {
+            domain_pause_for_debugger();
+        } else {
+            hvm_inject_hw_exception(TRAP_debug, HVM_DELIVER_NO_ERROR_CODE);
+        }
+    } 
+    if (vector == TRAP_int3) {
+        rc = vmxit_int3(regs);
+
+    }  else if (vector == TRAP_invalid_op) {
+        rc = vmxit_invalid_op(regs);
+
+    } else if (vector == TRAP_no_device) {
+        hvm_funcs.fpu_dirty_intercept();  /* calls vmx_fpu_dirty_intercept */
+        rc = 0;
+
+    } else if (vector == TRAP_gp_fault) {
+        regs->error_code = __vmread(VM_EXIT_INTR_ERROR_CODE);
+        /* hvm_inject_hw_exception(TRAP_gp_fault, regs->error_code); */
+        rc = 1;
+
+    } else if (vector == TRAP_page_fault) {
+        printk("PVH: Unexpected vector page_fault. IP:%lx\n", regs->eip);
+        rc = 1;
+    }
+    if (rc)
+        printk("PVH: Unhandled trap vector:%d. IP:%lx\n", vector, regs->eip);
+
+    return rc;
+}
+
+static int vmxit_invlpg(void)
+{
+    ulong vaddr = __vmread(EXIT_QUALIFICATION);
+
+    vmx_update_guest_eip();
+    vpid_sync_vcpu_gva(current, vaddr);
+    return 0;
+}
+
+static int vmxit_vmcall(struct cpu_user_regs *regs)
+{
+    if ( pvh_do_hypercall(regs) != HVM_HCALL_preempted)
+        vmx_update_guest_eip();
+
+    return 0;;
+}
+
+/* Returns: rc == 0: success */
+static int access_cr0(struct cpu_user_regs *regs, uint acc_typ, 
+                      uint64_t *regp)
+{
+    struct vcpu *vp = current;
+
+    if (acc_typ == VMX_CONTROL_REG_ACCESS_TYPE_MOV_TO_CR )
+    {
+        unsigned long new_cr0 = *regp;
+        unsigned long old_cr0 = __vmread(GUEST_CR0);
+
+        dbgp2("PVH:writing to CR0. RIP:%lx val:0x%lx\n", regs->rip, *regp);
+        if ( (u32)new_cr0 != new_cr0 )
+        {
+            HVM_DBG_LOG(DBG_LEVEL_1, 
+                        "Guest setting upper 32 bits in CR0: %lx", new_cr0);
+            return 1;
+        }
+
+        new_cr0 &= ~HVM_CR0_GUEST_RESERVED_BITS;
+        /* ET is reserved and should be always be 1. */
+        new_cr0 |= X86_CR0_ET;
+
+        /* pvh cannot change to real mode */
+        if ( (new_cr0 & (X86_CR0_PE|X86_CR0_PG)) != (X86_CR0_PG|X86_CR0_PE) ) {
+            printk("PVH attempting to turn off PE/PG. CR0:%lx\n", new_cr0);
+            return 1;
+        }
+        /* TS going from 1 to 0 */
+        if ( (old_cr0 & X86_CR0_TS) && ((new_cr0 & X86_CR0_TS)==0) )
+            vmx_fpu_enter(vp);
+
+        vp->arch.hvm_vcpu.hw_cr[0] = vp->arch.hvm_vcpu.guest_cr[0] = new_cr0;
+        __vmwrite(GUEST_CR0, new_cr0);
+        __vmwrite(CR0_READ_SHADOW, new_cr0);
+    } else {
+        *regp = __vmread(GUEST_CR0);
+    } 
+    return 0;
+}
+
+/* Returns: rc == 0: success */
+static int access_cr4(struct cpu_user_regs *regs, uint acc_typ, 
+                      uint64_t *regp)
+{
+    if (acc_typ == VMX_CONTROL_REG_ACCESS_TYPE_MOV_TO_CR )
+    {
+        u64 old_cr4 = __vmread(GUEST_CR4);
+
+        if ( (old_cr4 ^ (*regp)) & (X86_CR4_PSE | X86_CR4_PGE | X86_CR4_PAE) )
+            vpid_sync_all();
+
+        /* pvh_verify_cr4_wr(*regp)); */
+        __vmwrite(GUEST_CR4, *regp);
+    } else {
+        *regp = __vmread(GUEST_CR4);
+    } 
+    return 0;
+}
+
+/* Returns: rc == 0: success */
+static int vmxit_cr_access(struct cpu_user_regs *regs)
+{
+    unsigned long exit_qualification = __vmread(EXIT_QUALIFICATION);
+    uint acc_typ = VMX_CONTROL_REG_ACCESS_TYPE(exit_qualification);
+    int cr, rc = 1;
+
+    switch ( acc_typ )
+    {
+        case VMX_CONTROL_REG_ACCESS_TYPE_MOV_TO_CR:
+        case VMX_CONTROL_REG_ACCESS_TYPE_MOV_FROM_CR:
+        {
+            uint gpr = VMX_CONTROL_REG_ACCESS_GPR(exit_qualification);
+            uint64_t *regp = decode_register(gpr, regs, 0);
+            cr = VMX_CONTROL_REG_ACCESS_NUM(exit_qualification);
+
+            if (regp == NULL)
+                break;
+
+            /* pl don't embed switch statements */
+            if (cr == 0)
+                rc = access_cr0(regs, acc_typ, regp);
+            else if (cr == 3) {
+                printk("PVH: d%d: unexpected cr3 access vmexit. rip:%lx\n", 
+                       current->domain->domain_id, regs->rip);
+                domain_crash_synchronous();
+            } else if (cr == 4) 
+                rc = access_cr4(regs, acc_typ, regp);
+
+            if (rc == 0)
+                vmx_update_guest_eip();
+            break;
+        }
+        case VMX_CONTROL_REG_ACCESS_TYPE_CLTS:
+        {
+            struct vcpu *vp = current;
+            unsigned long cr0 = vp->arch.hvm_vcpu.guest_cr[0] & ~X86_CR0_TS;
+            vp->arch.hvm_vcpu.hw_cr[0] = vp->arch.hvm_vcpu.guest_cr[0] = cr0;
+            vmx_fpu_enter(vp);
+            __vmwrite(GUEST_CR0, cr0);
+            __vmwrite(CR0_READ_SHADOW, cr0);
+            vmx_update_guest_eip();
+            rc = 0;
+        }
+    }
+    return rc;
+}
+
+/* NOTE: a PVH sets IOPL natively by setting bits in the eflags and not by
+ * hypercalls used by a PV */
+static int vmxit_io_instr(struct cpu_user_regs *regs)
+{
+    int curr_lvl;
+    int requested = (regs->rflags >> 12) & 3;
+
+    read_vmcs_selectors(regs);
+    curr_lvl = regs->cs & 3;
+
+    if (requested >= curr_lvl && emulate_privileged_op(regs)) 
+        return 0;
+
+    hvm_inject_hw_exception(TRAP_gp_fault, regs->error_code);
+    return 0;
+}
+
+static int pvh_ept_handle_violation(unsigned long qualification, 
+                                    paddr_t gpa, struct cpu_user_regs *regs)
+{
+    unsigned long gla, gfn = gpa >> PAGE_SHIFT;
+    p2m_type_t p2mt;
+    mfn_t mfn = get_gfn_query_unlocked(current->domain, gfn, &p2mt);
+
+    gdprintk(XENLOG_ERR, "Dom:%d EPT violation %#lx (%c%c%c/%c%c%c), "
+             "gpa %#"PRIpaddr", mfn %#lx, type %i. IP:0x%lx RSP:0x%lx\n",
+             current->domain->domain_id, qualification, 
+             (qualification & EPT_READ_VIOLATION) ? 'r' : '-',
+             (qualification & EPT_WRITE_VIOLATION) ? 'w' : '-',
+             (qualification & EPT_EXEC_VIOLATION) ? 'x' : '-',
+             (qualification & EPT_EFFECTIVE_READ) ? 'r' : '-',
+             (qualification & EPT_EFFECTIVE_WRITE) ? 'w' : '-',
+             (qualification & EPT_EFFECTIVE_EXEC) ? 'x' : '-',
+             gpa, mfn_x(mfn), p2mt, regs->rip, regs->rsp);
+             
+    ept_walk_table(current->domain, gfn);
+
+    if ( qualification & EPT_GLA_VALID )
+    {
+        gla = __vmread(GUEST_LINEAR_ADDRESS);
+        gdprintk(XENLOG_ERR, " --- GLA %#lx\n", gla);
+    }
+
+    hvm_inject_hw_exception(TRAP_gp_fault, 0);
+    return 0;
+}
+
+static void pvh_user_cpuid(struct cpu_user_regs *regs)
+{
+    unsigned int eax, ebx, ecx, edx;
+
+    asm volatile ( "cpuid"
+              : "=a" (eax), "=b" (ebx), "=c" (ecx), "=d" (edx)
+              : "0" (regs->eax), "2" (regs->rcx) );
+
+    regs->rax = eax; regs->rbx = ebx; regs->rcx = ecx; regs->rdx = edx;
+}
+
+/* 
+ * Main exit handler for PVH case. Called from vmx_vmexit_handler(). 
+ * Note: in vmx_asm_vmexit_handler, rip/rsp/eflags are updated in regs{} 
+ */
+void vmx_pvh_vmexit_handler(struct cpu_user_regs *regs)
+{
+    unsigned long exit_qualification;
+    unsigned int exit_reason = __vmread(VM_EXIT_REASON);
+    int rc=0, ccpu = smp_processor_id();
+    struct vcpu *vp = current;
+
+    dbgp1("PVH:[%d]left VMCS exitreas:%d RIP:%lx RSP:%lx EFLAGS:%lx CR0:%lx\n", 
+          ccpu, exit_reason, regs->rip, regs->rsp, regs->rflags, 
+          __vmread(GUEST_CR0));
+
+    /* for guest_kernel_mode() */
+    regs->cs = __vmread(GUEST_CS_SELECTOR); 
+
+    switch ( (uint16_t)exit_reason )
+    {
+        case EXIT_REASON_EXCEPTION_NMI:      /* 0 */
+            rc = vmxit_exception(regs);
+            break;
+            
+        case EXIT_REASON_EXTERNAL_INTERRUPT: /* 1 */
+        case EXIT_REASON_MCE_DURING_VMENTRY: /* 41 */
+            break;              /* handled in vmx_vmexit_handler() */
+
+        case EXIT_REASON_TRIPLE_FAULT:       /* 2 */
+        {
+            printk("PVH:Triple Flt:[%d] RIP:%lx RSP:%lx EFLAGS:%lx CR3:%lx\n",
+                   ccpu, regs->rip, regs->rsp, regs->rflags, 
+                   __vmread(GUEST_CR3));
+
+            rc = 1;
+            break;
+        }
+        case EXIT_REASON_PENDING_VIRT_INTR:  /* 7 */
+        {
+            struct vcpu *v = current;
+
+            /* Disable the interrupt window. */
+            v->arch.hvm_vmx.exec_control &= ~CPU_BASED_VIRTUAL_INTR_PENDING;
+            __vmwrite(CPU_BASED_VM_EXEC_CONTROL, v->arch.hvm_vmx.exec_control);
+            break;
+        }
+
+        case EXIT_REASON_CPUID:              /* 10 */
+        {
+            if ( guest_kernel_mode(vp, regs) ) {
+                pv_cpuid(regs);
+            } else
+                pvh_user_cpuid(regs);
+
+            vmx_update_guest_eip();
+            dbgp2("cpuid:%ld RIP:%lx\n", regs->eax, regs->rip);
+            break;
+        }
+
+        case EXIT_REASON_HLT:             /* 12 */
+        {
+            vmx_update_guest_eip();
+            hvm_hlt(regs->eflags);
+            break;
+        }
+
+        case EXIT_REASON_INVLPG:             /* 14 */
+            rc = vmxit_invlpg();
+            break;
+
+        case EXIT_REASON_RDTSC:              /* 16 */
+            rc = 1;
+            break;
+
+        case EXIT_REASON_VMCALL:             /* 18 */
+            rc = vmxit_vmcall(regs);
+            break;
+
+        case EXIT_REASON_CR_ACCESS:          /* 28 */
+            rc = vmxit_cr_access(regs);
+            break;
+
+        case EXIT_REASON_DR_ACCESS:          /* 29 */
+        {
+            exit_qualification = __vmread(EXIT_QUALIFICATION);
+            vmx_dr_access(exit_qualification, regs);
+            break;
+        }
+
+        case EXIT_REASON_IO_INSTRUCTION:
+            vmxit_io_instr(regs);
+            break;
+
+        case EXIT_REASON_MSR_READ:           /* 31 */
+            rc = vmxit_msr_read(regs);
+            break;
+
+        case EXIT_REASON_MSR_WRITE:          /* 32 */
+            rc = vmxit_msr_write(regs);
+            break;
+
+        case EXIT_REASON_MONITOR_TRAP_FLAG:  /* 37 */
+            rc = vmxit_mtf(regs);
+            break;
+
+        case EXIT_REASON_EPT_VIOLATION:
+        {
+            paddr_t gpa = __vmread(GUEST_PHYSICAL_ADDRESS);
+            exit_qualification = __vmread(EXIT_QUALIFICATION);
+            rc = pvh_ept_handle_violation(exit_qualification, gpa, regs);
+            break;
+        }
+        default: 
+            rc = 1;
+            printk("PVH: Unexpected exit reason:%d 0x%x\n", exit_reason, 
+                   exit_reason);
+    }
+    if (rc) {
+        exit_qualification = __vmread(EXIT_QUALIFICATION);
+        printk("PVH: [%d] exit_reas:%d 0x%x qual:%ld 0x%lx cr0:0x%016lx\n", 
+             ccpu, exit_reason, exit_reason, exit_qualification,
+             exit_qualification, __vmread(GUEST_CR0));
+        printk("PVH: [%d] RIP:%lx RSP:%lx\n", ccpu, regs->rip, regs->rsp);
+        domain_crash_synchronous();
+    }
+}
+
+/* 
+ * Sets info for non boot vcpu. VCPU 0 context is set by library.
+ * We use this for nonboot vcpu in which case the call comes from the 
+ * kernel cpu_initialize_context().
+ */
+int vmx_pvh_set_vcpu_info(struct vcpu *v, struct vcpu_guest_context *ctxtp)
+{
+    if (v->vcpu_id == 0)
+        return 0;
+
+    vmx_vmcs_enter(v);
+    __vmwrite(GUEST_GDTR_BASE, ctxtp->u.pvh.gdtaddr);
+    __vmwrite(GUEST_GDTR_LIMIT, ctxtp->u.pvh.gdtsz);
+    __vmwrite(GUEST_GS_BASE, ctxtp->gs_base_user);
+
+    __vmwrite(GUEST_CS_SELECTOR, ctxtp->user_regs.cs);
+    __vmwrite(GUEST_DS_SELECTOR, ctxtp->user_regs.ds);
+    __vmwrite(GUEST_ES_SELECTOR, ctxtp->user_regs.es);
+    __vmwrite(GUEST_SS_SELECTOR, ctxtp->user_regs.ss);
+    __vmwrite(GUEST_GS_SELECTOR, ctxtp->user_regs.gs);
+
+    if ( vmx_add_guest_msr(MSR_SHADOW_GS_BASE) )
+        return -EINVAL;
+
+    vmx_write_guest_msr(MSR_SHADOW_GS_BASE, ctxtp->gs_base_kernel);
+
+    vmx_vmcs_exit(v);
+    return 0;
+}
+
+int vmx_pvh_read_descriptor(unsigned int sel, const struct vcpu *v,
+                            const struct cpu_user_regs *regs,
+                            unsigned long *base, unsigned long *limit,
+                            unsigned int *ar)
+{
+    unsigned int tmp_ar = 0;
+    BUG_ON(v!=current);
+    BUG_ON(!is_pvh_vcpu(v));
+
+    if (sel == (unsigned int)regs->cs) {
+        *base = __vmread(GUEST_CS_BASE);
+        *limit = __vmread(GUEST_CS_LIMIT);
+        tmp_ar = __vmread(GUEST_CS_AR_BYTES); 
+    } else if (sel == (unsigned int)regs->ds) {
+        *base = __vmread(GUEST_DS_BASE);
+        *limit = __vmread(GUEST_DS_LIMIT);
+        tmp_ar = __vmread(GUEST_DS_AR_BYTES); 
+    } else if (sel == (unsigned int)regs->ss) {
+        *base = __vmread(GUEST_SS_BASE);
+        *limit = __vmread(GUEST_SS_LIMIT);
+        tmp_ar = __vmread(GUEST_SS_AR_BYTES); 
+    } else if (sel == (unsigned int)regs->gs) {
+        *base = __vmread(GUEST_GS_BASE);
+        *limit = __vmread(GUEST_GS_LIMIT);
+        tmp_ar = __vmread(GUEST_GS_AR_BYTES); 
+    } else if (sel == (unsigned int)regs->fs) {
+        *base = __vmread(GUEST_FS_BASE);
+        *limit = __vmread(GUEST_FS_LIMIT);
+        tmp_ar = __vmread(GUEST_FS_AR_BYTES); 
+    } else if (sel == (unsigned int)regs->es) {
+        *base = __vmread(GUEST_ES_BASE);
+        *limit = __vmread(GUEST_ES_LIMIT);
+        tmp_ar = __vmread(GUEST_ES_AR_BYTES); 
+    } else {
+        printk("Unmatched segment selector:%d\n", sel);
+        return 0;
+    }
+
+    if (tmp_ar & X86_SEG_AR_CS_LM_ACTIVE) {           /* x86 mess!! */
+        *base = 0UL;
+        *limit = ~0UL;
+    }
+    /* Fixup ar so that it looks the same as in native mode */
+    *ar = (tmp_ar << 8);
+    return 1;
+}
+
diff --git a/xen/include/asm-x86/hvm/vmx/vmx.h b/xen/include/asm-x86/hvm/vmx/vmx.h
index a742e16..5679e8d 100644
--- a/xen/include/asm-x86/hvm/vmx/vmx.h
+++ b/xen/include/asm-x86/hvm/vmx/vmx.h
@@ -189,6 +189,7 @@ void vmx_update_secondary_exec_control(struct vcpu *v);
  * Access Rights
  */
 #define X86_SEG_AR_SEG_TYPE     0xf        /* 3:0, segment type */
+#define X86_SEG_AR_SEG_TYPE_CODE (1u << 3) /* code (vs data) segment */
 #define X86_SEG_AR_DESC_TYPE    (1u << 4)  /* 4, descriptor type */
 #define X86_SEG_AR_DPL          0x60       /* 6:5, descriptor privilege level */
 #define X86_SEG_AR_SEG_PRESENT  (1u << 7)  /* 7, segment present */
@@ -442,10 +443,14 @@ void ept_p2m_uninit(struct p2m_domain *p2m);
 
 void ept_walk_table(struct domain *d, unsigned long gfn);
 void setup_ept_dump(void);
-
 void vmx_update_guest_eip(void);
 void vmx_dr_access(unsigned long exit_qualification,struct cpu_user_regs *regs);
 void vmx_do_extint(struct cpu_user_regs *regs);
+void vmx_pvh_vmexit_handler(struct cpu_user_regs *regs);
+int  vmx_pvh_set_vcpu_info(struct vcpu *v, struct vcpu_guest_context *ctxtp);
+int  vmx_pvh_read_descriptor(unsigned int sel, const struct vcpu *v,
+                         const struct cpu_user_regs *regs, unsigned long *base,
+                         unsigned long *limit, unsigned int *ar);
 
 int alloc_p2m_hap_data(struct p2m_domain *p2m);
 void free_p2m_hap_data(struct p2m_domain *p2m);
diff --git a/xen/include/asm-x86/pvh.h b/xen/include/asm-x86/pvh.h
new file mode 100644
index 0000000..73e59d3
--- /dev/null
+++ b/xen/include/asm-x86/pvh.h
@@ -0,0 +1,6 @@
+#ifndef __ASM_X86_PVH_H__
+#define __ASM_X86_PVH_H__
+
+int pvh_do_hypercall(struct cpu_user_regs *regs);
+
+#endif  /* __ASM_X86_PVH_H__ */
-- 
1.7.2.3