From: Denis Mukhin <dmukhin@ford.com>
Current design enables all HVM domains share the same I/O port bitmap.
It is necessary for domains crafting its own I/O port address space depending
on the user configuration.
Ensure NS16550 emulator does not share I/O ports with the physical I/O ports,
which is essential for emulation in PVH hwdom case (dom0).
Not a functional change.
Signed-off-by: Denis Mukhin <dmukhin@ford.com>
---
Changes since v5:
- fixed printout formatters in ns16x50_init()
- Link to v5: https://lore.kernel.org/xen-devel/20250828235409.2835815-14-dmukhin@ford.com/
---
xen/arch/x86/Makefile | 1 +
xen/arch/x86/dom0_build.c | 111 +--------------
xen/arch/x86/hvm/hvm.c | 35 +----
xen/arch/x86/hvm/nestedhvm.c | 8 +-
xen/arch/x86/hvm/quirks.c | 3 -
xen/arch/x86/hvm/svm/nestedsvm.c | 2 +-
xen/arch/x86/hvm/vmx/vvmx.c | 4 +-
xen/arch/x86/include/asm/hvm/nestedhvm.h | 3 +-
xen/arch/x86/include/asm/hvm/support.h | 2 -
xen/arch/x86/include/asm/iocap.h | 2 +
xen/arch/x86/ioport.c | 163 +++++++++++++++++++++++
xen/arch/x86/pv/dom0_build.c | 4 +
xen/common/emul/vuart/ns16x50.c | 11 ++
13 files changed, 200 insertions(+), 149 deletions(-)
create mode 100644 xen/arch/x86/ioport.c
diff --git a/xen/arch/x86/Makefile b/xen/arch/x86/Makefile
index d7aed7d92c15..85a8475e126c 100644
--- a/xen/arch/x86/Makefile
+++ b/xen/arch/x86/Makefile
@@ -44,6 +44,7 @@ obj-y += msi.o
obj-y += msr.o
obj-$(CONFIG_INDIRECT_THUNK) += indirect-thunk.o
obj-$(CONFIG_RETURN_THUNK) += indirect-thunk.o
+obj-y += ioport.o
obj-$(CONFIG_PV) += ioport_emulate.o
obj-y += irq.o
obj-$(CONFIG_KEXEC) += machine_kexec.o
diff --git a/xen/arch/x86/dom0_build.c b/xen/arch/x86/dom0_build.c
index 0b467fd4a4fc..26202b33345c 100644
--- a/xen/arch/x86/dom0_build.c
+++ b/xen/arch/x86/dom0_build.c
@@ -298,9 +298,6 @@ int __init parse_arch_dom0_param(const char *s, const char *e)
return 0;
}
-static char __initdata opt_dom0_ioports_disable[200] = "";
-string_param("dom0_ioports_disable", opt_dom0_ioports_disable);
-
static bool __initdata ro_hpet = true;
boolean_param("ro-hpet", ro_hpet);
@@ -433,122 +430,20 @@ unsigned long __init dom0_compute_nr_pages(
return nr_pages;
}
-static void __init process_dom0_ioports_disable(struct domain *dom0)
-{
- unsigned long io_from, io_to;
- char *t, *s = opt_dom0_ioports_disable;
- const char *u;
-
- if ( *s == '\0' )
- return;
-
- while ( (t = strsep(&s, ",")) != NULL )
- {
- io_from = simple_strtoul(t, &u, 16);
- if ( u == t )
- {
- parse_error:
- printk("Invalid ioport range <%s> "
- "in dom0_ioports_disable, skipping\n", t);
- continue;
- }
-
- if ( *u == '\0' )
- io_to = io_from;
- else if ( *u == '-' )
- io_to = simple_strtoul(u + 1, &u, 16);
- else
- goto parse_error;
-
- if ( (*u != '\0') || (io_to < io_from) || (io_to >= 65536) )
- goto parse_error;
-
- printk("Disabling dom0 access to ioport range %04lx-%04lx\n",
- io_from, io_to);
-
- if ( ioports_deny_access(dom0, io_from, io_to) != 0 )
- BUG();
- }
-}
-
+/* Modify I/O memory access permissions. */
int __init dom0_setup_permissions(struct domain *d)
{
unsigned long mfn;
- unsigned int i, offs;
- int rc;
+ unsigned int i;
+ int rc = 0;
if ( pv_shim )
return 0;
- /* The hardware domain is initially permitted full I/O capabilities. */
- rc = ioports_permit_access(d, 0, 0xFFFF);
rc |= iomem_permit_access(d, 0UL,
PFN_DOWN(1UL << domain_max_paddr_bits(d)) - 1);
rc |= irqs_permit_access(d, 1, nr_irqs_gsi - 1);
- /* Modify I/O port access permissions. */
-
- for ( offs = 0, i = ISOLATE_LSB(i8259A_alias_mask) ?: 2;
- offs <= i8259A_alias_mask; offs += i )
- {
- if ( offs & ~i8259A_alias_mask )
- continue;
- /* Master Interrupt Controller (PIC). */
- rc |= ioports_deny_access(d, 0x20 + offs, 0x21 + offs);
- /* Slave Interrupt Controller (PIC). */
- rc |= ioports_deny_access(d, 0xA0 + offs, 0xA1 + offs);
- }
-
- /* ELCR of both PICs. */
- rc |= ioports_deny_access(d, 0x4D0, 0x4D1);
-
- /* Interval Timer (PIT). */
- for ( offs = 0, i = ISOLATE_LSB(pit_alias_mask) ?: 4;
- offs <= pit_alias_mask; offs += i )
- if ( !(offs & ~pit_alias_mask) )
- rc |= ioports_deny_access(d, PIT_CH0 + offs, PIT_MODE + offs);
-
- /* PIT Channel 2 / PC Speaker Control. */
- rc |= ioports_deny_access(d, 0x61, 0x61);
-
- /* INIT# and alternative A20M# control. */
- rc |= ioports_deny_access(d, 0x92, 0x92);
-
- /* IGNNE# control. */
- rc |= ioports_deny_access(d, 0xF0, 0xF0);
-
- /* ACPI PM Timer. */
- if ( pmtmr_ioport )
- rc |= ioports_deny_access(d, pmtmr_ioport, pmtmr_ioport + 3);
-
- /* Reset control. */
- rc |= ioports_deny_access(d, 0xCF9, 0xCF9);
-
- /* PCI configuration space (NB. 0xCF8 has special treatment). */
- rc |= ioports_deny_access(d, 0xCFC, 0xCFF);
-
-#ifdef CONFIG_HVM
- if ( is_hvm_domain(d) )
- {
- /* ISA DMA controller, channels 0-3 (incl possible aliases). */
- rc |= ioports_deny_access(d, 0x00, 0x1F);
- /* ISA DMA controller, page registers (incl various reserved ones). */
- rc |= ioports_deny_access(d, 0x80 + !!hvm_port80_allowed, 0x8F);
- /* ISA DMA controller, channels 4-7 (incl usual aliases). */
- rc |= ioports_deny_access(d, 0xC0, 0xDF);
-
- /* HVM debug console IO port. */
- rc |= ioports_deny_access(d, XEN_HVM_DEBUGCONS_IOPORT,
- XEN_HVM_DEBUGCONS_IOPORT);
- if ( amd_acpi_c1e_quirk )
- rc |= ioports_deny_access(d, acpi_smi_cmd, acpi_smi_cmd);
- }
-#endif
- /* Command-line I/O ranges. */
- process_dom0_ioports_disable(d);
-
- /* Modify I/O memory access permissions. */
-
/* Local APIC. */
if ( mp_lapic_addr != 0 )
{
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 91c971f11e14..93109db77283 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -51,6 +51,7 @@
#include <asm/hvm/vm_event.h>
#include <asm/hvm/vpt.h>
#include <asm/i387.h>
+#include <asm/iocap.h>
#include <asm/mc146818rtc.h>
#include <asm/mce.h>
#include <asm/monitor.h>
@@ -81,14 +82,6 @@ integer_param("hvm_debug", opt_hvm_debug_level);
struct hvm_function_table __ro_after_init hvm_funcs;
-/*
- * The I/O permission bitmap is globally shared by all HVM guests except
- * the hardware domain which needs a more permissive one.
- */
-#define HVM_IOBITMAP_SIZE (3 * PAGE_SIZE)
-unsigned long __section(".bss.page_aligned") __aligned(PAGE_SIZE)
- hvm_io_bitmap[HVM_IOBITMAP_SIZE / BYTES_PER_LONG];
-
/* Xen command-line option to enable HAP */
static bool __initdata opt_hap_enabled = true;
boolean_param("hap", opt_hap_enabled);
@@ -205,15 +198,6 @@ static int __init cf_check hvm_enable(void)
if ( opt_hvm_fep )
warning_add(warning_hvm_fep);
- /*
- * Allow direct access to the PC debug ports 0x80 and 0xed (they are
- * often used for I/O delays, but the vmexits simply slow things down).
- */
- memset(hvm_io_bitmap, ~0, sizeof(hvm_io_bitmap));
- if ( hvm_port80_allowed )
- __clear_bit(0x80, hvm_io_bitmap);
- __clear_bit(0xed, hvm_io_bitmap);
-
register_cpu_notifier(&cpu_nfb);
return 0;
@@ -645,19 +629,12 @@ int hvm_domain_initialise(struct domain *d,
rwlock_init(&d->arch.hvm.pl_time->pt_migrate);
- /* Set the default IO Bitmap. */
- if ( is_hardware_domain(d) )
+ rc = ioports_setup_access(d);
+ if ( rc )
{
- d->arch.hvm.io_bitmap = _xmalloc(HVM_IOBITMAP_SIZE, PAGE_SIZE);
- if ( d->arch.hvm.io_bitmap == NULL )
- {
- rc = -ENOMEM;
- goto fail1;
- }
- memset(d->arch.hvm.io_bitmap, ~0, HVM_IOBITMAP_SIZE);
+ printk("%pd failed to setup I/O bitmap: %d\n", d, rc);
+ goto fail1;
}
- else
- d->arch.hvm.io_bitmap = hvm_io_bitmap;
register_g2m_portio_handler(d);
register_vpci_portio_handler(d);
@@ -684,6 +661,8 @@ int hvm_domain_initialise(struct domain *d,
break;
}
+ BUG_ON(!d->arch.ioport_caps);
+
vpic_init(d);
rc = vioapic_init(d);
diff --git a/xen/arch/x86/hvm/nestedhvm.c b/xen/arch/x86/hvm/nestedhvm.c
index bddd77d8109b..d4e03123d910 100644
--- a/xen/arch/x86/hvm/nestedhvm.c
+++ b/xen/arch/x86/hvm/nestedhvm.c
@@ -107,7 +107,7 @@ nestedhvm_vmcx_flushtlb(struct p2m_domain *p2m)
* The users of the bitmap patterns are in SVM/VMX specific code.
*
* bitmap port 0x80 port 0xed
- * hvm_io_bitmap cleared cleared
+ * hvm.io_bitmap cleared cleared
* iomap[0] cleared set
* iomap[1] set cleared
* iomap[2] set set
@@ -115,7 +115,7 @@ nestedhvm_vmcx_flushtlb(struct p2m_domain *p2m)
static int __init cf_check nestedhvm_setup(void)
{
- /* Same format and size as hvm_io_bitmap (Intel needs only 2 pages). */
+ /* Same format and size as hvm.io_bitmap (Intel needs only 2 pages). */
unsigned nr = cpu_has_vmx ? 2 : 3;
unsigned int i, order = get_order_from_pages(nr);
@@ -165,7 +165,7 @@ static int __init cf_check nestedhvm_setup(void)
__initcall(nestedhvm_setup);
unsigned long *
-nestedhvm_vcpu_iomap_get(bool ioport_80, bool ioport_ed)
+nestedhvm_vcpu_iomap_get(struct vcpu *v, bool ioport_80, bool ioport_ed)
{
int i;
@@ -174,7 +174,7 @@ nestedhvm_vcpu_iomap_get(bool ioport_80, bool ioport_ed)
if (ioport_80 == 0) {
if (ioport_ed == 0)
- return hvm_io_bitmap;
+ return v->domain->arch.hvm.io_bitmap;
i = 0;
} else {
if (ioport_ed == 0)
diff --git a/xen/arch/x86/hvm/quirks.c b/xen/arch/x86/hvm/quirks.c
index 9202f5a47fe9..f4d95441fcff 100644
--- a/xen/arch/x86/hvm/quirks.c
+++ b/xen/arch/x86/hvm/quirks.c
@@ -73,9 +73,6 @@ static int __init cf_check check_port80(void)
dmi_check_system(hvm_no_port80_dmi_table);
- if ( !hvm_port80_allowed )
- __set_bit(0x80, hvm_io_bitmap);
-
return 0;
}
__initcall(check_port80);
diff --git a/xen/arch/x86/hvm/svm/nestedsvm.c b/xen/arch/x86/hvm/svm/nestedsvm.c
index dc2b6a42534a..cc8500b61665 100644
--- a/xen/arch/x86/hvm/svm/nestedsvm.c
+++ b/xen/arch/x86/hvm/svm/nestedsvm.c
@@ -381,7 +381,7 @@ static int nsvm_vmrun_permissionmap(struct vcpu *v, bool viopm)
hvm_unmap_guest_frame(ns_viomap, 0);
}
- svm->ns_iomap = nestedhvm_vcpu_iomap_get(ioport_80, ioport_ed);
+ svm->ns_iomap = nestedhvm_vcpu_iomap_get(v, ioport_80, ioport_ed);
nv->nv_ioport80 = ioport_80;
nv->nv_ioportED = ioport_ed;
diff --git a/xen/arch/x86/hvm/vmx/vvmx.c b/xen/arch/x86/hvm/vmx/vvmx.c
index e4f3a5fe4c71..4da3e6e90e6c 100644
--- a/xen/arch/x86/hvm/vmx/vvmx.c
+++ b/xen/arch/x86/hvm/vmx/vvmx.c
@@ -554,7 +554,7 @@ unsigned long *_shadow_io_bitmap(struct vcpu *v)
port80 = bitmap[0x80 >> 3] & (1 << (0x80 & 0x7)) ? 1 : 0;
portED = bitmap[0xed >> 3] & (1 << (0xed & 0x7)) ? 1 : 0;
- return nestedhvm_vcpu_iomap_get(port80, portED);
+ return nestedhvm_vcpu_iomap_get(v, port80, portED);
}
static void update_msrbitmap(struct vcpu *v, uint32_t shadow_ctrl)
@@ -622,7 +622,7 @@ void nvmx_update_exec_control(struct vcpu *v, u32 host_cntrl)
* L1 VMM doesn't intercept IO instruction.
* Use host configuration and reset IO_BITMAP
*/
- bitmap = hvm_io_bitmap;
+ bitmap = v->domain->arch.hvm.io_bitmap;
}
else {
/* use IO bitmap */
diff --git a/xen/arch/x86/include/asm/hvm/nestedhvm.h b/xen/arch/x86/include/asm/hvm/nestedhvm.h
index ea2c1bc328c7..d691ccb07dd6 100644
--- a/xen/arch/x86/include/asm/hvm/nestedhvm.h
+++ b/xen/arch/x86/include/asm/hvm/nestedhvm.h
@@ -50,7 +50,8 @@ int nestedhvm_hap_nested_page_fault(struct vcpu *v, paddr_t *L2_gpa,
struct npfec npfec);
/* IO permission map */
-unsigned long *nestedhvm_vcpu_iomap_get(bool ioport_80, bool ioport_ed);
+unsigned long *nestedhvm_vcpu_iomap_get(struct vcpu *v,
+ bool ioport_80, bool ioport_ed);
/* Misc */
#define nestedhvm_paging_mode_hap(v) (!!nhvm_vmcx_hap_enabled(v))
diff --git a/xen/arch/x86/include/asm/hvm/support.h b/xen/arch/x86/include/asm/hvm/support.h
index 2a7ba36af06f..7e36d00cc188 100644
--- a/xen/arch/x86/include/asm/hvm/support.h
+++ b/xen/arch/x86/include/asm/hvm/support.h
@@ -41,8 +41,6 @@ extern unsigned int opt_hvm_debug_level;
#define HVM_DBG_LOG(level, _f, _a...) do {} while (0)
#endif
-extern unsigned long hvm_io_bitmap[];
-
enum hvm_translation_result {
HVMTRANS_okay,
HVMTRANS_bad_linear_to_gfn,
diff --git a/xen/arch/x86/include/asm/iocap.h b/xen/arch/x86/include/asm/iocap.h
index f948b7186e95..1083f6171cf7 100644
--- a/xen/arch/x86/include/asm/iocap.h
+++ b/xen/arch/x86/include/asm/iocap.h
@@ -22,6 +22,8 @@
#define cache_flush_permitted(d) \
(has_arch_io_resources(d) || has_arch_pdevs(d))
+int ioports_setup_access(struct domain *d);
+
static inline int ioports_permit_access(struct domain *d, unsigned long s,
unsigned long e)
{
diff --git a/xen/arch/x86/ioport.c b/xen/arch/x86/ioport.c
new file mode 100644
index 000000000000..dbcd52d37a4f
--- /dev/null
+++ b/xen/arch/x86/ioport.c
@@ -0,0 +1,163 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Guest I/O port address space configuration.
+ *
+ * Copyright 2025 Ford Motor Company
+ */
+
+#include <xen/domain.h>
+#include <xen/param.h>
+
+#include <asm/amd.h>
+#include <asm/acpi.h>
+#include <asm/io-ports.h>
+#include <asm/iocap.h>
+#include <asm/pv/shim.h>
+#include <asm/setup.h>
+
+static char __initdata opt_dom0_ioports_disable[200] = "";
+string_param("dom0_ioports_disable", opt_dom0_ioports_disable);
+
+/*
+ * The I/O permission bitmap size.
+ * See: comment in nestedhvm_setup()
+ */
+#define HVM_IOBITMAP_SIZE (3 * PAGE_SIZE)
+
+/* Hide user-defined I/O ports from the guest OS. */
+static void process_dom0_ioports_disable(struct domain *dom0)
+{
+ unsigned long io_from, io_to;
+ char *t, *s = opt_dom0_ioports_disable;
+ const char *u;
+
+ if ( *s == '\0' )
+ return;
+
+ while ( (t = strsep(&s, ",")) != NULL )
+ {
+ io_from = simple_strtoul(t, &u, 16);
+ if ( u == t )
+ {
+ parse_error:
+ printk("Invalid ioport range <%s> "
+ "in dom0_ioports_disable, skipping\n", t);
+ continue;
+ }
+
+ if ( *u == '\0' )
+ io_to = io_from;
+ else if ( *u == '-' )
+ io_to = simple_strtoul(u + 1, &u, 16);
+ else
+ goto parse_error;
+
+ if ( (*u != '\0') || (io_to < io_from) || (io_to >= 65536) )
+ goto parse_error;
+
+ printk("Disabling dom0 access to ioport range %04lx-%04lx\n",
+ io_from, io_to);
+
+ if ( ioports_deny_access(dom0, io_from, io_to) != 0 )
+ BUG();
+ }
+}
+
+/* Set the default IO Bitmap. */
+int ioports_setup_access(struct domain *d)
+{
+ unsigned int i, offs;
+ int rc;
+
+ if ( pv_shim )
+ return 0;
+
+#ifdef CONFIG_HVM
+ d->arch.hvm.io_bitmap = _xmalloc(HVM_IOBITMAP_SIZE, PAGE_SIZE);
+ if ( d->arch.hvm.io_bitmap == NULL )
+ return -ENOMEM;
+
+ memset(d->arch.hvm.io_bitmap, ~0, HVM_IOBITMAP_SIZE);
+
+ if ( !is_hardware_domain(d) )
+ {
+ /*
+ * Allow direct access to the PC debug ports 0x80 and 0xed (they are
+ * often used for I/O delays, but the vmexits simply slow things down).
+ */
+ if ( hvm_port80_allowed )
+ __clear_bit(0x80, d->arch.hvm.io_bitmap);
+
+ __clear_bit(0xed, d->arch.hvm.io_bitmap);
+
+ return 0;
+ }
+#endif
+
+ /* The hardware domain is initially permitted full I/O capabilities. */
+ rc = ioports_permit_access(d, 0, 0xFFFF);
+
+ /* Modify I/O port access permissions. */
+
+ for ( offs = 0, i = ISOLATE_LSB(i8259A_alias_mask) ?: 2;
+ offs <= i8259A_alias_mask; offs += i )
+ {
+ if ( offs & ~i8259A_alias_mask )
+ continue;
+ /* Master Interrupt Controller (PIC). */
+ rc |= ioports_deny_access(d, 0x20 + offs, 0x21 + offs);
+ /* Slave Interrupt Controller (PIC). */
+ rc |= ioports_deny_access(d, 0xA0 + offs, 0xA1 + offs);
+ }
+
+ /* ELCR of both PICs. */
+ rc |= ioports_deny_access(d, 0x4D0, 0x4D1);
+
+ /* Interval Timer (PIT). */
+ for ( offs = 0, i = ISOLATE_LSB(pit_alias_mask) ?: 4;
+ offs <= pit_alias_mask; offs += i )
+ if ( !(offs & ~pit_alias_mask) )
+ rc |= ioports_deny_access(d, PIT_CH0 + offs, PIT_MODE + offs);
+
+ /* PIT Channel 2 / PC Speaker Control. */
+ rc |= ioports_deny_access(d, 0x61, 0x61);
+
+ /* INIT# and alternative A20M# control. */
+ rc |= ioports_deny_access(d, 0x92, 0x92);
+
+ /* IGNNE# control. */
+ rc |= ioports_deny_access(d, 0xF0, 0xF0);
+
+ /* ACPI PM Timer. */
+ if ( pmtmr_ioport )
+ rc |= ioports_deny_access(d, pmtmr_ioport, pmtmr_ioport + 3);
+
+ /* Reset control. */
+ rc |= ioports_deny_access(d, 0xCF9, 0xCF9);
+
+ /* PCI configuration space (NB. 0xCF8 has special treatment). */
+ rc |= ioports_deny_access(d, 0xCFC, 0xCFF);
+
+#ifdef CONFIG_HVM
+ if ( is_hvm_domain(d) )
+ {
+ /* ISA DMA controller, channels 0-3 (incl possible aliases). */
+ rc |= ioports_deny_access(d, 0x00, 0x1F);
+ /* ISA DMA controller, page registers (incl various reserved ones). */
+ rc |= ioports_deny_access(d, 0x80 + !!hvm_port80_allowed, 0x8F);
+ /* ISA DMA controller, channels 4-7 (incl usual aliases). */
+ rc |= ioports_deny_access(d, 0xC0, 0xDF);
+
+ /* HVM debug console IO port. */
+ rc |= ioports_deny_access(d, XEN_HVM_DEBUGCONS_IOPORT,
+ XEN_HVM_DEBUGCONS_IOPORT);
+ if ( amd_acpi_c1e_quirk )
+ rc |= ioports_deny_access(d, acpi_smi_cmd, acpi_smi_cmd);
+ }
+#endif
+
+ /* Command-line I/O ranges. */
+ process_dom0_ioports_disable(d);
+
+ return rc;
+}
diff --git a/xen/arch/x86/pv/dom0_build.c b/xen/arch/x86/pv/dom0_build.c
index 21158ce1812e..2b8b4d869ee7 100644
--- a/xen/arch/x86/pv/dom0_build.c
+++ b/xen/arch/x86/pv/dom0_build.c
@@ -17,6 +17,7 @@
#include <asm/bootinfo.h>
#include <asm/bzimage.h>
#include <asm/dom0_build.h>
+#include <asm/iocap.h>
#include <asm/guest.h>
#include <asm/page.h>
#include <asm/pv/mm.h>
@@ -1033,6 +1034,9 @@ static int __init dom0_construct(const struct boot_domain *bd)
if ( test_bit(XENFEAT_supervisor_mode_kernel, parms.f_required) )
panic("Dom0 requires supervisor-mode execution\n");
+ rc = ioports_setup_access(d);
+ BUG_ON(rc != 0);
+
rc = dom0_setup_permissions(d);
BUG_ON(rc != 0);
diff --git a/xen/common/emul/vuart/ns16x50.c b/xen/common/emul/vuart/ns16x50.c
index a4fa3a9be713..7c4affe98533 100644
--- a/xen/common/emul/vuart/ns16x50.c
+++ b/xen/common/emul/vuart/ns16x50.c
@@ -792,9 +792,20 @@ static int ns16x50_init(void *arg)
struct vuart_ns16x50 *vdev = arg;
const struct vuart_info *info = vdev->info;
struct domain *d = vdev->owner;
+ int rc;
ASSERT(vdev);
+ /* Disallow sharing physical I/O port */
+ rc = ioports_deny_access(d, info->base_addr,
+ info->base_addr + info->size - 1);
+ if ( rc )
+ {
+ ns16x50_err(info, " virtual I/O port range [0x%04lx..0x%04lx]: conflict w/ physical range\n",
+ info->base_addr, info->base_addr + info->size - 1);
+ return rc;
+ }
+
/* NB: report 115200 baud rate. */
vdev->regs[NS16X50_REGS_NUM + UART_DLL] = divisor & 0xff;
vdev->regs[NS16X50_REGS_NUM + UART_DLM] = (divisor >> 8) & 0xff;
--
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