[PATCH kvmtool 08/21] x86/ioport: Refactor trap handlers

Andre Przywara
2020-12-10T19:09:03Z

With the planned retirement of the special ioport emulation code, we
need to provide emulation functions compatible with the MMIO
prototype.

Adjust the trap handlers to use that new function, and provide shims to
implement the old ioport interface, for now.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
---
x86/ioport.c | 30 ++++++++++++++++++++++++++----
1 file changed, 26 insertions(+), 4 deletions(-)

diff --git a/x86/ioport.c b/x86/ioport.c
index 8c5c7699..932da20a 100644
--- a/x86/ioport.c
+++ b/x86/ioport.c
@@ -3,8 +3,14 @@
#include <stdlib.h>
#include <stdio.h>

+static void dummy_mmio(struct kvm_cpu *vcpu, u64 addr, u8 *data, u32 len,
+ u8 is_write, void *ptr)
+{
+}
+
static bool debug_io_out(struct ioport *ioport, struct kvm_cpu *vcpu, u16 port, void *data, int size)
{
+ dummy_mmio(vcpu, port, data, size, true, NULL);
return 0;
}

@@ -12,15 +18,23 @@ static struct ioport_operations debug_ops = {
.io_out = debug_io_out,
};

-static bool seabios_debug_io_out(struct ioport *ioport, struct kvm_cpu *vcpu, u16 port, void *data, int size)
+static void seabios_debug_mmio(struct kvm_cpu *vcpu, u64 addr, u8 *data,
+ u32 len, u8 is_write, void *ptr)
{
char ch;

+ if (!is_write)
+ return;
+
ch = ioport__read8(data);

putchar(ch);
+}

- return true;
+static bool seabios_debug_io_out(struct ioport *ioport, struct kvm_cpu *vcpu, u16 port, void *data, int size)
+{
+ seabios_debug_mmio(vcpu, port, data, size, true, NULL);
+ return 0;
}

static struct ioport_operations seabios_debug_ops = {
@@ -29,11 +43,13 @@ static struct ioport_operations seabios_debug_ops = {

static bool dummy_io_in(struct ioport *ioport, struct kvm_cpu *vcpu, u16 port, void *data, int size)
{
+ dummy_mmio(vcpu, port, data, size, false, NULL);
return true;
}

static bool dummy_io_out(struct ioport *ioport, struct kvm_cpu *vcpu, u16 port, void *data, int size)
{
+ dummy_mmio(vcpu, port, data, size, true, NULL);
return true;
}

@@ -50,13 +66,19 @@ static struct ioport_operations dummy_write_only_ioport_ops = {
* The "fast A20 gate"
*/

-static bool ps2_control_a_io_in(struct ioport *ioport, struct kvm_cpu *vcpu, u16 port, void *data, int size)
+static void ps2_control_mmio(struct kvm_cpu *vcpu, u64 addr, u8 *data, u32 len,
+ u8 is_write, void *ptr)
{
/*
* A20 is always enabled.
*/
- ioport__write8(data, 0x02);
+ if (!is_write)
+ ioport__write8(data, 0x02);
+}

+static bool ps2_control_a_io_in(struct ioport *ioport, struct kvm_cpu *vcpu, u16 port, void *data, int size)
+{
+ ps2_control_mmio(vcpu, port, data, size, false, NULL);
return true;
}

--
2.17.1