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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen staging] xen/arm: Allow vpl011 to be used by DomU
commit 1ee1e4b0d1ffa29795f4ab2d025d70128b864676
Author: Stefano Stabellini <sstabellini@xxxxxxxxxx>
AuthorDate: Tue Nov 13 09:49:32 2018 -0800
Commit: Julien Grall <julien.grall@xxxxxxx>
CommitDate: Wed Nov 14 19:34:48 2018 +0000
xen/arm: Allow vpl011 to be used by DomU
Make vpl011 being able to be used without a userspace component in Dom0.
In that case, output is printed to the Xen serial and input is received
from the Xen serial one character at a time.
Call domain_vpl011_init during construct_domU if vpl011 is enabled.
Introduce a new ring struct with only the ring array to avoid a waste of
memory. Introduce separate read_data and write_data functions for
initial domains: vpl011_write_data_xen is very simple and just writes
to the console, while vpl011_read_data_xen is a duplicate of
vpl011_read_data. Although textually almost identical, we are forced to
duplicate the functions because the struct layout is different.
To avoid mixing the output of different domains on the console, buffer
the output chars and print line by line. Unless the domain has input
from the serial, in which case we want to print char by char for a
smooth user experience.
The size of SBSA_UART_OUT_BUF_SIZE is arbitrary, choose the same size
as VUART_BUF_SIZE used in vuart.c.
Export a function named console_input_domain() to allow others to know
which domains has input at a given time.
Signed-off-by: Stefano Stabellini <stefanos@xxxxxxxxxx>
Acked-by: Julien Grall <julien.grall@xxxxxxx>
---
xen/arch/arm/domain_build.c | 9 +-
xen/arch/arm/vpl011.c | 231 ++++++++++++++++++++++++++++++++++++++-----
xen/drivers/char/console.c | 10 +-
xen/include/asm-arm/vpl011.h | 12 +++
xen/include/xen/console.h | 2 +
5 files changed, 238 insertions(+), 26 deletions(-)
diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index cd4a2c7de7..61a8419427 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -2631,7 +2631,14 @@ static int __init construct_domU(struct domain *d,
if ( rc < 0 )
return rc;
- return construct_domain(d, &kinfo);
+ rc = construct_domain(d, &kinfo);
+ if ( rc < 0 )
+ return rc;
+
+ if ( kinfo.vpl011 )
+ rc = domain_vpl011_init(d, NULL);
+
+ return rc;
}
void __init create_domUs(void)
diff --git a/xen/arch/arm/vpl011.c b/xen/arch/arm/vpl011.c
index e29515a3b6..7bc5eeb207 100644
--- a/xen/arch/arm/vpl011.c
+++ b/xen/arch/arm/vpl011.c
@@ -28,6 +28,7 @@
#include <xen/lib.h>
#include <xen/mm.h>
#include <xen/sched.h>
+#include <xen/console.h>
#include <public/domctl.h>
#include <public/io/console.h>
#include <asm/pl011-uart.h>
@@ -78,6 +79,121 @@ static void vpl011_update_interrupt_status(struct domain *d)
#endif
}
+/*
+ * vpl011_write_data_xen writes chars from the vpl011 out buffer to the
+ * console. Only to be used when the backend is Xen.
+ */
+static void vpl011_write_data_xen(struct domain *d, uint8_t data)
+{
+ unsigned long flags;
+ struct vpl011 *vpl011 = &d->arch.vpl011;
+ struct vpl011_xen_backend *intf = vpl011->backend.xen;
+ struct domain *input = console_input_domain();
+
+ VPL011_LOCK(d, flags);
+
+ intf->out[intf->out_prod++] = data;
+ if ( d == input )
+ {
+ if ( intf->out_prod == 1 )
+ {
+ printk("%c", data);
+ intf->out_prod = 0;
+ }
+ else
+ {
+ if ( data != '\n' )
+ intf->out[intf->out_prod++] = '\n';
+ intf->out[intf->out_prod++] = '\0';
+ printk("%s", intf->out);
+ intf->out_prod = 0;
+ }
+ }
+ else
+ {
+ if ( intf->out_prod == SBSA_UART_OUT_BUF_SIZE - 2 ||
+ data == '\n' )
+ {
+ if ( data != '\n' )
+ intf->out[intf->out_prod++] = '\n';
+ intf->out[intf->out_prod++] = '\0';
+ printk("DOM%u: %s", d->domain_id, intf->out);
+ intf->out_prod = 0;
+ }
+ }
+
+ vpl011->uartris |= TXI;
+ vpl011->uartfr &= ~TXFE;
+ vpl011_update_interrupt_status(d);
+
+ VPL011_UNLOCK(d, flags);
+ if ( input != NULL )
+ rcu_unlock_domain(input);
+}
+
+/*
+ * vpl011_read_data_xen reads data when the backend is xen. Characters
+ * are added to the vpl011 receive buffer by vpl011_rx_char_xen.
+ */
+static uint8_t vpl011_read_data_xen(struct domain *d)
+{
+ unsigned long flags;
+ uint8_t data = 0;
+ struct vpl011 *vpl011 = &d->arch.vpl011;
+ struct vpl011_xen_backend *intf = vpl011->backend.xen;
+ XENCONS_RING_IDX in_cons, in_prod;
+
+ VPL011_LOCK(d, flags);
+
+ in_cons = intf->in_cons;
+ in_prod = intf->in_prod;
+
+ smp_rmb();
+
+ /*
+ * It is expected that there will be data in the ring buffer when this
+ * function is called since the guest is expected to read the data register
+ * only if the TXFE flag is not set.
+ * If the guest still does read when TXFE bit is set then 0 will be
returned.
+ */
+ if ( xencons_queued(in_prod, in_cons, sizeof(intf->in)) > 0 )
+ {
+ unsigned int fifo_level;
+
+ data = intf->in[xencons_mask(in_cons, sizeof(intf->in))];
+ in_cons += 1;
+ smp_mb();
+ intf->in_cons = in_cons;
+
+ fifo_level = xencons_queued(in_prod, in_cons, sizeof(intf->in));
+
+ /* If the FIFO is now empty, we clear the receive timeout interrupt. */
+ if ( fifo_level == 0 )
+ {
+ vpl011->uartfr |= RXFE;
+ vpl011->uartris &= ~RTI;
+ }
+
+ /* If the FIFO is more than half empty, we clear the RX interrupt. */
+ if ( fifo_level < sizeof(intf->in) - SBSA_UART_FIFO_LEVEL )
+ vpl011->uartris &= ~RXI;
+
+ vpl011_update_interrupt_status(d);
+ }
+ else
+ gprintk(XENLOG_ERR, "vpl011: Unexpected IN ring buffer empty\n");
+
+ /*
+ * We have consumed a character or the FIFO was empty, so clear the
+ * "FIFO full" bit.
+ */
+ vpl011->uartfr &= ~RXFF;
+
+ VPL011_UNLOCK(d, flags);
+
+ return data;
+}
+
static uint8_t vpl011_read_data(struct domain *d)
{
unsigned long flags;
@@ -241,7 +357,10 @@ static int vpl011_mmio_read(struct vcpu *v,
case DR:
if ( !vpl011_reg32_check_access(dabt) ) goto bad_width;
- *r = vreg_reg32_extract(vpl011_read_data(d), info);
+ if ( vpl011->backend_in_domain )
+ *r = vreg_reg32_extract(vpl011_read_data(d), info);
+ else
+ *r = vreg_reg32_extract(vpl011_read_data_xen(d), info);
return 1;
case RSR:
@@ -326,7 +445,10 @@ static int vpl011_mmio_write(struct vcpu *v,
vreg_reg32_update(&data, r, info);
data &= 0xFF;
- vpl011_write_data(v->domain, data);
+ if ( vpl011->backend_in_domain )
+ vpl011_write_data(v->domain, data);
+ else
+ vpl011_write_data_xen(v->domain, data);
return 1;
}
@@ -431,6 +553,39 @@ static void vpl011_data_avail(struct domain *d,
vpl011->uartfr |= TXFE;
}
+/*
+ * vpl011_rx_char_xen adds a char to a domain's vpl011 receive buffer.
+ * It is only used when the vpl011 backend is in Xen.
+ */
+void vpl011_rx_char_xen(struct domain *d, char c)
+{
+ unsigned long flags;
+ struct vpl011 *vpl011 = &d->arch.vpl011;
+ struct vpl011_xen_backend *intf = vpl011->backend.xen;
+ XENCONS_RING_IDX in_cons, in_prod, in_fifo_level;
+
+ ASSERT(!vpl011->backend_in_domain);
+ VPL011_LOCK(d, flags);
+
+ in_cons = intf->in_cons;
+ in_prod = intf->in_prod;
+ if ( xencons_queued(in_prod, in_cons, sizeof(intf->in)) ==
sizeof(intf->in) )
+ {
+ VPL011_UNLOCK(d, flags);
+ return;
+ }
+
+ intf->in[xencons_mask(in_prod, sizeof(intf->in))] = c;
+ intf->in_prod = ++in_prod;
+
+ in_fifo_level = xencons_queued(in_prod,
+ in_cons,
+ sizeof(intf->in));
+
+ vpl011_data_avail(d, in_fifo_level, sizeof(intf->in), 0,
SBSA_UART_FIFO_SIZE);
+ VPL011_UNLOCK(d, flags);
+}
+
static void vpl011_notification(struct vcpu *v, unsigned int port)
{
unsigned long flags;
@@ -471,27 +626,47 @@ int domain_vpl011_init(struct domain *d, struct
vpl011_init_info *info)
if ( vpl011->backend.dom.ring_buf )
return -EINVAL;
- /* Map the guest PFN to Xen address space. */
- rc = prepare_ring_for_helper(d,
- gfn_x(info->gfn),
- &vpl011->backend.dom.ring_page,
- &vpl011->backend.dom.ring_buf);
- if ( rc < 0 )
- goto out;
+ /*
+ * info is NULL when the backend is in Xen.
+ * info is != NULL when the backend is in a domain.
+ */
+ if ( info != NULL )
+ {
+ vpl011->backend_in_domain = true;
+
+ /* Map the guest PFN to Xen address space. */
+ rc = prepare_ring_for_helper(d,
+ gfn_x(info->gfn),
+ &vpl011->backend.dom.ring_page,
+ &vpl011->backend.dom.ring_buf);
+ if ( rc < 0 )
+ goto out;
+
+ rc = alloc_unbound_xen_event_channel(d, 0, info->console_domid,
+ vpl011_notification);
+ if ( rc < 0 )
+ goto out1;
+
+ vpl011->evtchn = info->evtchn = rc;
+ }
+ else
+ {
+ vpl011->backend_in_domain = false;
+
+ vpl011->backend.xen = xzalloc(struct vpl011_xen_backend);
+ if ( vpl011->backend.xen == NULL )
+ {
+ rc = -EINVAL;
+ goto out1;
+ }
+ }
rc = vgic_reserve_virq(d, GUEST_VPL011_SPI);
if ( !rc )
{
rc = -EINVAL;
- goto out1;
- }
-
- rc = alloc_unbound_xen_event_channel(d, 0, info->console_domid,
- vpl011_notification);
- if ( rc < 0 )
goto out2;
-
- vpl011->evtchn = info->evtchn = rc;
+ }
spin_lock_init(&vpl011->lock);
@@ -504,8 +679,11 @@ out2:
vgic_free_virq(d, GUEST_VPL011_SPI);
out1:
- destroy_ring_for_helper(&vpl011->backend.dom.ring_buf,
- vpl011->backend.dom.ring_page);
+ if ( vpl011->backend_in_domain )
+ destroy_ring_for_helper(&vpl011->backend.dom.ring_buf,
+ vpl011->backend.dom.ring_page);
+ else
+ xfree(vpl011->backend.xen);
out:
return rc;
@@ -515,12 +693,17 @@ void domain_vpl011_deinit(struct domain *d)
{
struct vpl011 *vpl011 = &d->arch.vpl011;
- if ( !vpl011->backend.dom.ring_buf )
- return;
+ if ( vpl011->backend_in_domain )
+ {
+ if ( !vpl011->backend.dom.ring_buf )
+ return;
- free_xen_event_channel(d, vpl011->evtchn);
- destroy_ring_for_helper(&vpl011->backend.dom.ring_buf,
- vpl011->backend.dom.ring_page);
+ free_xen_event_channel(d, vpl011->evtchn);
+ destroy_ring_for_helper(&vpl011->backend.dom.ring_buf,
+ vpl011->backend.dom.ring_page);
+ }
+ else
+ xfree(vpl011->backend.xen);
}
/*
diff --git a/xen/drivers/char/console.c b/xen/drivers/char/console.c
index 414d329c39..f39a37e025 100644
--- a/xen/drivers/char/console.c
+++ b/xen/drivers/char/console.c
@@ -406,6 +406,14 @@ static void dump_console_ring_key(unsigned char key)
*/
static unsigned int __read_mostly console_rx = 0;
+/* Make sure to rcu_unlock_domain after use */
+struct domain *console_input_domain(void)
+{
+ if ( console_rx == 0 )
+ return NULL;
+ return rcu_lock_domain_by_id(console_rx - 1);
+}
+
static void switch_serial_input(void)
{
if ( console_rx == max_init_domid + 1 )
@@ -447,7 +455,7 @@ static void __serial_rx(char c, struct cpu_user_regs *regs)
send_global_virq(VIRQ_CONSOLE);
break;
-#if 0
+#ifdef CONFIG_SBSA_VUART_CONSOLE
default:
{
struct domain *d = rcu_lock_domain_by_any_id(console_rx - 1);
diff --git a/xen/include/asm-arm/vpl011.h b/xen/include/asm-arm/vpl011.h
index a880bcfd99..e6c7ab7381 100644
--- a/xen/include/asm-arm/vpl011.h
+++ b/xen/include/asm-arm/vpl011.h
@@ -21,6 +21,7 @@
#include <public/domctl.h>
#include <public/io/ring.h>
+#include <public/io/console.h>
#include <xen/mm.h>
/* helper macros */
@@ -28,13 +29,23 @@
#define VPL011_UNLOCK(d,flags) spin_unlock_irqrestore(&(d)->arch.vpl011.lock,
flags)
#define SBSA_UART_FIFO_SIZE 32
+/* Same size as VUART_BUF_SIZE, used in vuart.c */
+#define SBSA_UART_OUT_BUF_SIZE 128
+struct vpl011_xen_backend {
+ char in[SBSA_UART_FIFO_SIZE];
+ char out[SBSA_UART_OUT_BUF_SIZE];
+ XENCONS_RING_IDX in_cons, in_prod;
+ XENCONS_RING_IDX out_prod;
+};
struct vpl011 {
+ bool backend_in_domain;
union {
struct {
void *ring_buf;
struct page_info *ring_page;
} dom;
+ struct vpl011_xen_backend *xen;
} backend;
uint32_t uartfr; /* Flag register */
uint32_t uartcr; /* Control register */
@@ -56,6 +67,7 @@ struct vpl011_init_info {
int domain_vpl011_init(struct domain *d,
struct vpl011_init_info *info);
void domain_vpl011_deinit(struct domain *d);
+void vpl011_rx_char_xen(struct domain *d, char c);
#else
static inline int domain_vpl011_init(struct domain *d,
struct vpl011_init_info *info)
diff --git a/xen/include/xen/console.h b/xen/include/xen/console.h
index 70c9911a49..c5a85c8f6a 100644
--- a/xen/include/xen/console.h
+++ b/xen/include/xen/console.h
@@ -31,6 +31,8 @@ void console_end_sync(void);
void console_start_log_everything(void);
void console_end_log_everything(void);
+struct domain *console_input_domain(void);
+
/*
* Steal output from the console. Returns +ve identifier, else -ve error.
* Takes the handle of the serial line to steal, and steal callback function.
--
generated by git-patchbot for /home/xen/git/xen.git#staging
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