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i386/tcg: implement x2APIC registers MSR access
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This commit creates apic_register_read/write which are used by both
apic_mem_read/write for MMIO access and apic_msr_read/write for MSR access.

The apic_msr_read/write returns -1 on error, accelerator can use this to
raise the appropriate exception.

Signed-off-by: Bui Quang Minh <minhquangbui99@gmail.com>
Message-Id: <20240111154404.5333-2-minhquangbui99@gmail.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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@minhbq-99 @mstsirkin
minhbq-99 authored and mstsirkin committed Feb 14, 2024
1 parent bad3872 commit b210135
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Showing 5 changed files with 127 additions and 32 deletions.
122 changes: 92 additions & 30 deletions hw/intc/apic.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -288,6 +288,13 @@ void apic_deliver_irq(uint8_t dest, uint8_t dest_mode, uint8_t delivery_mode,
apic_bus_deliver(deliver_bitmask, delivery_mode, vector_num, trigger_mode);
}

bool is_x2apic_mode(DeviceState *dev)
{
APICCommonState *s = APIC(dev);

return s->apicbase & MSR_IA32_APICBASE_EXTD;
}

static void apic_set_base(APICCommonState *s, uint64_t val)
{
s->apicbase = (val & 0xfffff000) |
Expand Down Expand Up @@ -636,24 +643,19 @@ static void apic_timer(void *opaque)
apic_timer_update(s, s->next_time);
}

static uint64_t apic_mem_read(void *opaque, hwaddr addr, unsigned size)
static int apic_register_read(int index, uint64_t *value)
{
DeviceState *dev;
APICCommonState *s;
uint32_t val;
int index;

if (size < 4) {
return 0;
}
int ret = 0;

dev = cpu_get_current_apic();
if (!dev) {
return 0;
return -1;
}
s = APIC(dev);

index = (addr >> 4) & 0xff;
switch(index) {
case 0x02: /* id */
val = s->id << 24;
Expand Down Expand Up @@ -718,12 +720,46 @@ static uint64_t apic_mem_read(void *opaque, hwaddr addr, unsigned size)
default:
s->esr |= APIC_ESR_ILLEGAL_ADDRESS;
val = 0;
ret = -1;
break;
}
trace_apic_mem_readl(addr, val);

trace_apic_register_read(index, val);
*value = val;
return ret;
}

static uint64_t apic_mem_read(void *opaque, hwaddr addr, unsigned size)
{
uint64_t val;
int index;

if (size < 4) {
return 0;
}

index = (addr >> 4) & 0xff;
apic_register_read(index, &val);

return val;
}

int apic_msr_read(int index, uint64_t *val)
{
DeviceState *dev;

dev = cpu_get_current_apic();
if (!dev) {
return -1;
}

if (!is_x2apic_mode(dev)) {
return -1;
}

return apic_register_read(index, val);
}

static void apic_send_msi(MSIMessage *msi)
{
uint64_t addr = msi->address;
Expand All @@ -737,35 +773,18 @@ static void apic_send_msi(MSIMessage *msi)
apic_deliver_irq(dest, dest_mode, delivery, vector, trigger_mode);
}

static void apic_mem_write(void *opaque, hwaddr addr, uint64_t val,
unsigned size)
static int apic_register_write(int index, uint64_t val)
{
DeviceState *dev;
APICCommonState *s;
int index = (addr >> 4) & 0xff;

if (size < 4) {
return;
}

if (addr > 0xfff || !index) {
/* MSI and MMIO APIC are at the same memory location,
* but actually not on the global bus: MSI is on PCI bus
* APIC is connected directly to the CPU.
* Mapping them on the global bus happens to work because
* MSI registers are reserved in APIC MMIO and vice versa. */
MSIMessage msi = { .address = addr, .data = val };
apic_send_msi(&msi);
return;
}

dev = cpu_get_current_apic();
if (!dev) {
return;
return -1;
}
s = APIC(dev);

trace_apic_mem_writel(addr, val);
trace_apic_register_write(index, val);

switch(index) {
case 0x02:
Expand Down Expand Up @@ -839,8 +858,51 @@ static void apic_mem_write(void *opaque, hwaddr addr, uint64_t val,
break;
default:
s->esr |= APIC_ESR_ILLEGAL_ADDRESS;
break;
return -1;
}

return 0;
}

static void apic_mem_write(void *opaque, hwaddr addr, uint64_t val,
unsigned size)
{
int index = (addr >> 4) & 0xff;

if (size < 4) {
return;
}

if (addr > 0xfff || !index) {
/*
* MSI and MMIO APIC are at the same memory location,
* but actually not on the global bus: MSI is on PCI bus
* APIC is connected directly to the CPU.
* Mapping them on the global bus happens to work because
* MSI registers are reserved in APIC MMIO and vice versa.
*/
MSIMessage msi = { .address = addr, .data = val };
apic_send_msi(&msi);
return;
}

apic_register_write(index, val);
}

int apic_msr_write(int index, uint64_t val)
{
DeviceState *dev;

dev = cpu_get_current_apic();
if (!dev) {
return -1;
}

if (!is_x2apic_mode(dev)) {
return -1;
}

return apic_register_write(index, val);
}

static void apic_pre_save(APICCommonState *s)
Expand Down
4 changes: 2 additions & 2 deletions hw/intc/trace-events
View file
Original file line number Diff line number Diff line change
Expand Up @@ -14,8 +14,8 @@ cpu_get_apic_base(uint64_t val) "0x%016"PRIx64
# apic.c
apic_local_deliver(int vector, uint32_t lvt) "vector %d delivery mode %d"
apic_deliver_irq(uint8_t dest, uint8_t dest_mode, uint8_t delivery_mode, uint8_t vector_num, uint8_t trigger_mode) "dest %d dest_mode %d delivery_mode %d vector %d trigger_mode %d"
apic_mem_readl(uint64_t addr, uint32_t val) "0x%"PRIx64" = 0x%08x"
apic_mem_writel(uint64_t addr, uint32_t val) "0x%"PRIx64" = 0x%08x"
apic_register_read(uint8_t reg, uint64_t val) "register 0x%02x = 0x%"PRIx64
apic_register_write(uint8_t reg, uint64_t val) "register 0x%02x = 0x%"PRIx64

# ioapic.c
ioapic_set_remote_irr(int n) "set remote irr for pin %d"
Expand Down
3 changes: 3 additions & 0 deletions include/hw/i386/apic.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -18,6 +18,9 @@ void apic_sipi(DeviceState *s);
void apic_poll_irq(DeviceState *d);
void apic_designate_bsp(DeviceState *d, bool bsp);
int apic_get_highest_priority_irr(DeviceState *dev);
int apic_msr_read(int index, uint64_t *val);
int apic_msr_write(int index, uint64_t val);
bool is_x2apic_mode(DeviceState *d);

/* pc.c */
DeviceState *cpu_get_current_apic(void);
Expand Down
3 changes: 3 additions & 0 deletions target/i386/cpu.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -545,6 +545,9 @@ typedef enum X86Seg {
#define MSR_IA32_VMX_TRUE_ENTRY_CTLS 0x00000490
#define MSR_IA32_VMX_VMFUNC 0x00000491

#define MSR_APIC_START 0x00000800
#define MSR_APIC_END 0x000008ff

#define XSTATE_FP_BIT 0
#define XSTATE_SSE_BIT 1
#define XSTATE_YMM_BIT 2
Expand Down
27 changes: 27 additions & 0 deletions target/i386/tcg/sysemu/misc_helper.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -25,6 +25,7 @@
#include "exec/address-spaces.h"
#include "exec/exec-all.h"
#include "tcg/helper-tcg.h"
#include "hw/i386/apic.h"

void helper_outb(CPUX86State *env, uint32_t port, uint32_t data)
{
Expand Down Expand Up @@ -289,6 +290,19 @@ void helper_wrmsr(CPUX86State *env)
env->msr_bndcfgs = val;
cpu_sync_bndcs_hflags(env);
break;
case MSR_APIC_START ... MSR_APIC_END: {
int ret;
int index = (uint32_t)env->regs[R_ECX] - MSR_APIC_START;

bql_lock();
ret = apic_msr_write(index, val);
bql_unlock();
if (ret < 0) {
goto error;
}

break;
}
default:
if ((uint32_t)env->regs[R_ECX] >= MSR_MC0_CTL
&& (uint32_t)env->regs[R_ECX] < MSR_MC0_CTL +
Expand Down Expand Up @@ -455,6 +469,19 @@ void helper_rdmsr(CPUX86State *env)
val = (cs->nr_threads * cs->nr_cores) | (cs->nr_cores << 16);
break;
}
case MSR_APIC_START ... MSR_APIC_END: {
int ret;
int index = (uint32_t)env->regs[R_ECX] - MSR_APIC_START;

bql_lock();
ret = apic_msr_read(index, &val);
bql_unlock();
if (ret < 0) {
raise_exception_err_ra(env, EXCP0D_GPF, 0, GETPC());
}

break;
}
default:
if ((uint32_t)env->regs[R_ECX] >= MSR_MC0_CTL
&& (uint32_t)env->regs[R_ECX] < MSR_MC0_CTL +
Expand Down

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