[Xen-devel] [PATCH v6 05/12] x86/domctl: Handle ACPI access from domctl

[Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>]

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
---
Changes in v6:
* Adjustments to to patch 4 changes.
* Added a spinlock for VCPU map access
* Return an error on guest trying to write VCPU map

 xen/arch/x86/hvm/acpi.c          | 57 +++++++++++++++++++++++++++++++++++-----
 xen/include/asm-x86/hvm/domain.h |  1 +
 2 files changed, 52 insertions(+), 6 deletions(-)

diff --git a/xen/arch/x86/hvm/acpi.c b/xen/arch/x86/hvm/acpi.c
index f0a84f9..9f0578e 100644
--- a/xen/arch/x86/hvm/acpi.c
+++ b/xen/arch/x86/hvm/acpi.c
@@ -7,17 +7,22 @@
 #include <xen/lib.h>
 #include <xen/sched.h>
 
+#include <asm/guest_access.h>
+
 #include <public/arch-x86/xen.h>
 
-static int acpi_cpumap_access_common(struct domain *d, bool is_write,
-                                     unsigned int port,
+static int acpi_cpumap_access_common(struct domain *d, bool is_guest_access,
+                                     bool is_write, unsigned int port,
                                      unsigned int bytes, uint32_t *val)
 {
     unsigned int first_byte = port - XEN_ACPI_CPU_MAP;
+    int rc = X86EMUL_OKAY;
 
     BUILD_BUG_ON(XEN_ACPI_CPU_MAP + XEN_ACPI_CPU_MAP_LEN
                  > ACPI_GPE0_BLK_ADDRESS_V1);
 
+    spin_lock(&d->arch.hvm_domain.acpi_lock);
+
     if ( !is_write )
     {
         uint32_t mask = (bytes < 4) ? ~0U << (bytes * 8) : 0;
@@ -32,23 +37,61 @@ static int acpi_cpumap_access_common(struct domain *d, bool 
is_write,
             memcpy(val, (uint8_t *)d->avail_vcpus + first_byte,
                    min(bytes, ((d->max_vcpus + 7) / 8) - first_byte));
     }
+    else if ( !is_guest_access )
+        memcpy((uint8_t *)d->avail_vcpus + first_byte, val,
+               min(bytes, ((d->max_vcpus + 7) / 8) - first_byte));
     else
         /* Guests do not write CPU map */
-        return X86EMUL_UNHANDLEABLE;
+        rc = X86EMUL_UNHANDLEABLE;
 
-    return X86EMUL_OKAY;
+    spin_unlock(&d->arch.hvm_domain.acpi_lock);
+
+    return rc;
 }
 
 int hvm_acpi_domctl_access(struct domain *d,
                            const struct xen_domctl_acpi_access *access)
 {
-    return -ENOSYS;
+    unsigned int bytes, i;
+    uint32_t val = 0;
+    uint8_t *ptr = (uint8_t *)&val;
+    int rc;
+    bool is_write = (access->rw == XEN_DOMCTL_ACPI_WRITE) ? true : false;
+
+    if ( has_acpi_dm_ff(d) )
+        return -EOPNOTSUPP;
+
+    if ( access->space_id != XEN_ACPI_SYSTEM_IO )
+        return -EINVAL;
+
+    if ( !((access->address >= XEN_ACPI_CPU_MAP) &&
+           (access->address < XEN_ACPI_CPU_MAP + XEN_ACPI_CPU_MAP_LEN)) )
+        return -ENODEV;
+
+    for ( i = 0; i < access->width; i += sizeof(val) )
+    {
+        bytes = (access->width - i > sizeof(val)) ?
+            sizeof(val) : access->width - i;
+
+        if ( is_write && copy_from_guest_offset(ptr, access->val, i, bytes) )
+            return -EFAULT;
+
+        rc = acpi_cpumap_access_common(d, false, is_write,
+                                       access->address, bytes, &val);
+        if ( rc )
+            return rc;
+
+        if ( !is_write && copy_to_guest_offset(access->val, i, ptr, bytes) )
+            return -EFAULT;
+    }
+
+    return 0;
 }
 
 static int acpi_cpumap_guest_access(int dir, unsigned int port,
                                     unsigned int bytes, uint32_t *val)
 {
-    return  acpi_cpumap_access_common(current->domain,
+    return  acpi_cpumap_access_common(current->domain, true,
                                       (dir == IOREQ_WRITE) ? true : false,
                                       port, bytes, val);
 }
@@ -148,6 +191,8 @@ void hvm_acpi_init(struct domain *d)
                             sizeof(d->arch.hvm_domain.acpi.pm1a_sts) +
                             sizeof(d->arch.hvm_domain.acpi.pm1a_en),
                             acpi_guest_access);
+
+    spin_lock_init(&d->arch.hvm_domain.acpi_lock);
 }
 
 /*
diff --git a/xen/include/asm-x86/hvm/domain.h b/xen/include/asm-x86/hvm/domain.h
index 07815b6..438ea12 100644
--- a/xen/include/asm-x86/hvm/domain.h
+++ b/xen/include/asm-x86/hvm/domain.h
@@ -111,6 +111,7 @@ struct hvm_domain {
      */
 #define hvm_hw_acpi hvm_hw_pmtimer
     struct hvm_hw_acpi     acpi;
+    spinlock_t             acpi_lock;
 
     /* VCPU which is current target for 8259 interrupts. */
     struct vcpu           *i8259_target;
-- 
2.7.4


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