Commit 3bb28b72 authored by Jan Kiszka's avatar Jan Kiszka Committed by Paolo Bonzini
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memory: Provide separate handling of unassigned io ports accesses 



Accesses to unassigned io ports shall return -1 on read and be ignored
on write. Ensure these properties via dedicated ops, decoupling us from
the memory core's handling of unassigned accesses.

Cc: qemu-stable@nongnu.org
Signed-off-by: default avatarJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 88266249

exec.c

+2 −1
Original line number Diff line number Diff line
@@ -1805,7 +1805,8 @@ static void memory_map_init(void) 
    address_space_init(&address_space_memory, system_memory, "memory");



    system_io = g_malloc(sizeof(*system_io));

    memory_region_init(system_io, NULL, "io", 65536);

    memory_region_init_io(system_io, NULL, &unassigned_io_ops, NULL, "io",

                          65536);

    address_space_init(&address_space_io, system_io, "I/O");



    memory_listener_register(&core_memory_listener, &address_space_memory);

include/exec/ioport.h

+4 −0
Original line number Diff line number Diff line
@@ -45,6 +45,10 @@ typedef struct MemoryRegionPortio { 


#define PORTIO_END_OF_LIST() { }



#ifndef CONFIG_USER_ONLY

extern const MemoryRegionOps unassigned_io_ops;

#endif



void cpu_outb(pio_addr_t addr, uint8_t val);

void cpu_outw(pio_addr_t addr, uint16_t val);

void cpu_outl(pio_addr_t addr, uint32_t val);

ioport.c

+16 −0
Original line number Diff line number Diff line
@@ -44,6 +44,22 @@ typedef struct MemoryRegionPortioList { 
    MemoryRegionPortio ports[];

} MemoryRegionPortioList;



static uint64_t unassigned_io_read(void *opaque, hwaddr addr, unsigned size)

{

    return -1ULL;

}



static void unassigned_io_write(void *opaque, hwaddr addr, uint64_t val,

                                unsigned size)

{

}



const MemoryRegionOps unassigned_io_ops = {

    .read = unassigned_io_read,

    .write = unassigned_io_write,

    .endianness = DEVICE_NATIVE_ENDIAN,

};



void cpu_outb(pio_addr_t addr, uint8_t val)

{

    LOG_IOPORT("outb: %04"FMT_pioaddr" %02"PRIx8"\n", addr, val);