[PATCH v7 06/15] x86/hvm: unify dpci portio intercept with standard portio intercept

[Paul Durrant <paul.durrant@citrix.com>]

This patch re-works the dpci portio intercepts so that they can be unified
with standard portio handling thereby removing a substantial amount of
code duplication.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Cc: Keir Fraser <keir@xen.org>
Cc: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
---

v7:
- Cosmetic changes requested by Jan

v6:
- Added Andrew's reviewed-by

v5:
- Addressed further comments from Jan
---
 xen/arch/x86/hvm/hvm.c         |    2 +
 xen/arch/x86/hvm/intercept.c   |   16 +--
 xen/arch/x86/hvm/io.c          |  220 ++++++++++++----------------------------
 xen/include/asm-x86/hvm/io.h   |    4 +
 xen/include/asm-x86/hvm/vcpu.h |    2 +
 xen/include/xen/iommu.h        |    1 -
 6 files changed, 78 insertions(+), 167 deletions(-)

diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 1fd5efc..e0fca45 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -1482,6 +1482,8 @@ int hvm_domain_initialise(struct domain *d)
     else
         d->arch.hvm_domain.io_bitmap = hvm_io_bitmap;
 
+    register_dpci_portio_handler(d);
+
     if ( is_pvh_domain(d) )
     {
         register_portio_handler(d, 0, 0x10003, handle_pvh_io);
diff --git a/xen/arch/x86/hvm/intercept.c b/xen/arch/x86/hvm/intercept.c
index f9535ea..a1c4f29 100644
--- a/xen/arch/x86/hvm/intercept.c
+++ b/xen/arch/x86/hvm/intercept.c
@@ -119,8 +119,7 @@ int hvm_process_io_intercept(const struct hvm_io_handler *handler,
 {
     struct vcpu *curr = current;
     struct hvm_vcpu_io *vio = &curr->arch.hvm_vcpu.hvm_io;
-    const struct hvm_io_ops *ops = (p->type == IOREQ_TYPE_COPY) ?
-                                   &mmio_ops : &portio_ops;
+    const struct hvm_io_ops *ops = handler->ops;
     int rc = X86EMUL_OKAY, i, step = p->df ? -p->size : p->size;
     uint64_t data;
     uint64_t addr;
@@ -240,8 +239,6 @@ int hvm_process_io_intercept(const struct hvm_io_handler *handler,
 const struct hvm_io_handler *hvm_find_io_handler(ioreq_t *p)
 {
     struct domain *curr_d = current->domain;
-    const struct hvm_io_ops *ops = (p->type == IOREQ_TYPE_COPY) ?
-                                   &mmio_ops : &portio_ops;
     unsigned int i;
 
     BUG_ON((p->type != IOREQ_TYPE_PIO) &&
@@ -251,6 +248,7 @@ const struct hvm_io_handler *hvm_find_io_handler(ioreq_t *p)
     {
         const struct hvm_io_handler *handler =
             &curr_d->arch.hvm_domain.io_handler[i];
+        const struct hvm_io_ops *ops = handler->ops;
 
         if ( handler->type != p->type )
             continue;
@@ -266,13 +264,7 @@ int hvm_io_intercept(ioreq_t *p)
 {
     const struct hvm_io_handler *handler;
 
-    if ( p->type == IOREQ_TYPE_PIO )
-    {
-        int rc = dpci_ioport_intercept(p);
-        if ( (rc == X86EMUL_OKAY) || (rc == X86EMUL_RETRY) )
-            return rc;
-    }
-    else if ( p->type == IOREQ_TYPE_COPY )
+    if ( p->type == IOREQ_TYPE_COPY )
     {
         int rc = stdvga_intercept_mmio(p);
         if ( (rc == X86EMUL_OKAY) || (rc == X86EMUL_RETRY) )
@@ -306,6 +298,7 @@ void register_mmio_handler(struct domain *d,
     struct hvm_io_handler *handler = hvm_next_io_handler(d);
 
     handler->type = IOREQ_TYPE_COPY;
+    handler->ops = &mmio_ops;
     handler->mmio.ops = ops;
 }
 
@@ -315,6 +308,7 @@ void register_portio_handler(struct domain *d, uint16_t port,
     struct hvm_io_handler *handler = hvm_next_io_handler(d);
 
     handler->type = IOREQ_TYPE_PIO;
+    handler->ops = &portio_ops;
     handler->portio.port = port;
     handler->portio.size = size;
     handler->portio.action = action;
diff --git a/xen/arch/x86/hvm/io.c b/xen/arch/x86/hvm/io.c
index c0964ec..2c88ddb 100644
--- a/xen/arch/x86/hvm/io.c
+++ b/xen/arch/x86/hvm/io.c
@@ -208,185 +208,95 @@ void hvm_io_assist(ioreq_t *p)
     }
 }
 
-static int dpci_ioport_read(uint32_t mport, ioreq_t *p)
+static bool_t dpci_portio_accept(const struct hvm_io_handler *handler,
+                                 const ioreq_t *p)
 {
-    struct hvm_vcpu_io *vio = &current->arch.hvm_vcpu.hvm_io;
-    int rc = X86EMUL_OKAY, i, step = p->df ? -p->size : p->size;
-    uint32_t data = 0;
+    struct vcpu *curr = current;
+    struct hvm_iommu *hd = domain_hvm_iommu(curr->domain);
+    struct hvm_vcpu_io *vio = &curr->arch.hvm_vcpu.hvm_io;
+    struct g2m_ioport *g2m_ioport;
+    unsigned int start, end;
 
-    for ( i = 0; i < p->count; i++ )
+    list_for_each_entry( g2m_ioport, &hd->arch.g2m_ioport_list, list )
     {
-        if ( vio->mmio_retrying )
-        {
-            if ( vio->mmio_large_read_bytes != p->size )
-                return X86EMUL_UNHANDLEABLE;
-            memcpy(&data, vio->mmio_large_read, p->size);
-            vio->mmio_large_read_bytes = 0;
-            vio->mmio_retrying = 0;
-        }
-        else switch ( p->size )
+        start = g2m_ioport->gport;
+        end = start + g2m_ioport->np;
+        if ( (p->addr >= start) && (p->addr + p->size <= end) )
         {
-        case 1:
-            data = inb(mport);
-            break;
-        case 2:
-            data = inw(mport);
-            break;
-        case 4:
-            data = inl(mport);
-            break;
-        default:
-            BUG();
+            vio->g2m_ioport = g2m_ioport;
+            return 1;
         }
-
-        if ( p->data_is_ptr )
-        {
-            switch ( hvm_copy_to_guest_phys(p->data + step * i,
-                                            &data, p->size) )
-            {
-            case HVMCOPY_okay:
-                break;
-            case HVMCOPY_gfn_paged_out:
-            case HVMCOPY_gfn_shared:
-                rc = X86EMUL_RETRY;
-                break;
-            case HVMCOPY_bad_gfn_to_mfn:
-                /* Drop the write as real hardware would. */
-                continue;
-            case HVMCOPY_bad_gva_to_gfn:
-                ASSERT(0);
-                /* fall through */
-            default:
-                rc = X86EMUL_UNHANDLEABLE;
-                break;
-            }
-            if ( rc != X86EMUL_OKAY)
-                break;
-        }
-        else
-            p->data = data;
     }
 
-    if ( rc == X86EMUL_RETRY )
-    {
-        vio->mmio_retry = 1;
-        vio->mmio_large_read_bytes = p->size;
-        memcpy(vio->mmio_large_read, &data, p->size);
-    }
-
-    if ( i != 0 )
-    {
-        p->count = i;
-        rc = X86EMUL_OKAY;
-    }
-
-    return rc;
+    return 0;
 }
 
-static int dpci_ioport_write(uint32_t mport, ioreq_t *p)
+static int dpci_portio_read(const struct hvm_io_handler *handler,
+                            uint64_t addr,
+                            uint32_t size,
+                            uint64_t *data)
 {
-    int rc = X86EMUL_OKAY, i, step = p->df ? -p->size : p->size;
-    uint32_t data;
-
-    for ( i = 0; i < p->count; i++ )
-    {
-        data = p->data;
-        if ( p->data_is_ptr )
-        {
-            switch ( hvm_copy_from_guest_phys(&data, p->data + step * i,
-                                              p->size) )
-            {
-            case HVMCOPY_okay:
-                break;
-            case HVMCOPY_gfn_paged_out:
-            case HVMCOPY_gfn_shared:
-                rc = X86EMUL_RETRY;
-                break;
-            case HVMCOPY_bad_gfn_to_mfn:
-                data = ~0;
-                break;
-            case HVMCOPY_bad_gva_to_gfn:
-                ASSERT(0);
-                /* fall through */
-            default:
-                rc = X86EMUL_UNHANDLEABLE;
-                break;
-            }
-            if ( rc != X86EMUL_OKAY)
-                break;
-        }
-
-        switch ( p->size )
-        {
-        case 1:
-            outb(data, mport);
-            break;
-        case 2:
-            outw(data, mport);
-            break;
-        case 4:
-            outl(data, mport);
-            break;
-        default:
-            BUG();
-        }
-    }
-
-    if ( rc == X86EMUL_RETRY )
-        current->arch.hvm_vcpu.hvm_io.mmio_retry = 1;
+    struct hvm_vcpu_io *vio = &current->arch.hvm_vcpu.hvm_io;
+    const struct g2m_ioport *g2m_ioport = vio->g2m_ioport;
+    unsigned int mport = (addr - g2m_ioport->gport) + g2m_ioport->mport;
 
-    if ( i != 0 )
+    switch ( size )
     {
-        p->count = i;
-        rc = X86EMUL_OKAY;
+    case 1:
+        *data = inb(mport);
+        break;
+    case 2:
+        *data = inw(mport);
+        break;
+    case 4:
+        *data = inl(mport);
+        break;
+    default:
+        BUG();
     }
 
-    return rc;
+    return X86EMUL_OKAY;
 }
 
-int dpci_ioport_intercept(ioreq_t *p)
+static int dpci_portio_write(const struct hvm_io_handler *handler,
+                             uint64_t addr,
+                             uint32_t size,
+                             uint64_t data)
 {
-    struct domain *d = current->domain;
-    struct hvm_iommu *hd = domain_hvm_iommu(d);
-    struct g2m_ioport *g2m_ioport;
-    unsigned int mport, gport = p->addr;
-    unsigned int s = 0, e = 0;
-    int rc;
-
-    list_for_each_entry( g2m_ioport, &hd->arch.g2m_ioport_list, list )
-    {
-        s = g2m_ioport->gport;
-        e = s + g2m_ioport->np;
-        if ( (gport >= s) && (gport < e) )
-            goto found;
-    }
-
-    return X86EMUL_UNHANDLEABLE;
-
- found:
-    mport = (gport - s) + g2m_ioport->mport;
-
-    if ( !ioports_access_permitted(d, mport, mport + p->size - 1) ) 
-    {
-        gdprintk(XENLOG_ERR, "Error: access to gport=%#x denied!\n",
-                 (uint32_t)p->addr);
-        return X86EMUL_UNHANDLEABLE;
-    }
+    struct hvm_vcpu_io *vio = &current->arch.hvm_vcpu.hvm_io;
+    const struct g2m_ioport *g2m_ioport = vio->g2m_ioport;
+    unsigned int mport = (addr - g2m_ioport->gport) + g2m_ioport->mport;
 
-    switch ( p->dir )
+    switch ( size )
     {
-    case IOREQ_READ:
-        rc = dpci_ioport_read(mport, p);
+    case 1:
+        outb(data, mport);
         break;
-    case IOREQ_WRITE:
-        rc = dpci_ioport_write(mport, p);
+    case 2:
+        outw(data, mport);
+        break;
+    case 4:
+        outl(data, mport);
         break;
     default:
-        gdprintk(XENLOG_ERR, "Error: couldn't handle p->dir = %d", p->dir);
-        rc = X86EMUL_UNHANDLEABLE;
+        BUG();
     }
 
-    return rc;
+    return X86EMUL_OKAY;
+}
+
+static const struct hvm_io_ops dpci_portio_ops = {
+    .accept = dpci_portio_accept,
+    .read = dpci_portio_read,
+    .write = dpci_portio_write
+};
+
+void register_dpci_portio_handler(struct domain *d)
+{
+    struct hvm_io_handler *handler = hvm_next_io_handler(d);
+
+    handler->type = IOREQ_TYPE_PIO;
+    handler->ops = &dpci_portio_ops;
 }
 
 /*
diff --git a/xen/include/asm-x86/hvm/io.h b/xen/include/asm-x86/hvm/io.h
index a01502a..1288005 100644
--- a/xen/include/asm-x86/hvm/io.h
+++ b/xen/include/asm-x86/hvm/io.h
@@ -72,6 +72,7 @@ struct hvm_io_handler {
             portio_action_t action;
         } portio;
     };
+    const struct hvm_io_ops *ops;
     uint8_t type;
 };
 
@@ -144,6 +145,9 @@ int stdvga_intercept_mmio(ioreq_t *p);
 void stdvga_deinit(struct domain *d);
 
 extern void hvm_dpci_msi_eoi(struct domain *d, int vector);
+
+void register_dpci_portio_handler(struct domain *d);
+
 #endif /* __ASM_X86_HVM_IO_H__ */
 
 
diff --git a/xen/include/asm-x86/hvm/vcpu.h b/xen/include/asm-x86/hvm/vcpu.h
index 0faf60d..4ed285f 100644
--- a/xen/include/asm-x86/hvm/vcpu.h
+++ b/xen/include/asm-x86/hvm/vcpu.h
@@ -77,6 +77,8 @@ struct hvm_vcpu_io {
     bool_t mmio_retry, mmio_retrying;
 
     unsigned long msix_unmask_address;
+
+    const struct g2m_ioport *g2m_ioport;
 };
 
 #define VMCX_EADDR    (~0ULL)
diff --git a/xen/include/xen/iommu.h b/xen/include/xen/iommu.h
index b30bf41..1d00696 100644
--- a/xen/include/xen/iommu.h
+++ b/xen/include/xen/iommu.h
@@ -93,7 +93,6 @@ void pt_pci_init(void);
 
 struct pirq;
 int hvm_do_IRQ_dpci(struct domain *, struct pirq *);
-int dpci_ioport_intercept(ioreq_t *p);
 int pt_irq_create_bind(struct domain *, xen_domctl_bind_pt_irq_t *);
 int pt_irq_destroy_bind(struct domain *, xen_domctl_bind_pt_irq_t *);
 
-- 
1.7.10.4