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hw/i386/acpi-build: Return a pre-computed _PRT table

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When qemu runs without kvm acceleration the ACPI executions take a great
amount of time. If they take more than the default time (30sec), the
ACPI calls fail and the system might not behave correctly.

Now the _PRT table is computed on the fly. We can drastically reduce the
execution of the _PRT method if we return a pre-computed table.

Without this patch:
[   51.343484] ACPI Error: Aborting method \_SB.PCI0._PRT due to previous error (AE_AML_LOOP_TIMEOUT) (20230628/psparse-529)
[   51.527032] ACPI Error: Method execution failed \_SB.PCI0._PRT due to previous error (AE_AML_LOOP_TIMEOUT) (20230628/uteval-68)
[   51.530049] virtio-pci 0000:00:02.0: can't derive routing for PCI INT A
[   51.530797] virtio-pci 0000:00:02.0: PCI INT A: no GSI
[   81.922901] ACPI Error: Aborting method \_SB.PCI0._PRT due to previous error (AE_AML_LOOP_TIMEOUT) (20230628/psparse-529)
[   82.103534] ACPI Error: Method execution failed \_SB.PCI0._PRT due to previous error (AE_AML_LOOP_TIMEOUT) (20230628/uteval-68)
[   82.106088] virtio-pci 0000:00:04.0: can't derive routing for PCI INT A
[   82.106761] virtio-pci 0000:00:04.0: PCI INT A: no GSI
[  112.192568] ACPI Error: Aborting method \_SB.PCI0._PRT due to previous error (AE_AML_LOOP_TIMEOUT) (20230628/psparse-529)
[  112.486687] ACPI Error: Method execution failed \_SB.PCI0._PRT due to previous error (AE_AML_LOOP_TIMEOUT) (20230628/uteval-68)
[  112.489554] virtio-pci 0000:00:05.0: can't derive routing for PCI INT A
[  112.490027] virtio-pci 0000:00:05.0: PCI INT A: no GSI
[  142.559448] ACPI Error: Aborting method \_SB.PCI0._PRT due to previous error (AE_AML_LOOP_TIMEOUT) (20230628/psparse-529)
[  142.718596] ACPI Error: Method execution failed \_SB.PCI0._PRT due to previous error (AE_AML_LOOP_TIMEOUT) (20230628/uteval-68)
[  142.722889] virtio-pci 0000:00:06.0: can't derive routing for PCI INT A
[  142.724578] virtio-pci 0000:00:06.0: PCI INT A: no GSI

With this patch:
[   22.938076] ACPI: \_SB_.LNKB: Enabled at IRQ 10
[   24.214002] ACPI: \_SB_.LNKD: Enabled at IRQ 11
[   25.465170] ACPI: \_SB_.LNKA: Enabled at IRQ 10
[   27.944920] ACPI: \_SB_.LNKC: Enabled at IRQ 11

ACPI disassembly:
        Scope (PCI0)
        {
            Method (_PRT, 0, NotSerialized)  // _PRT: PCI Routing Table
            {
                Return (Package (0x80)
                {
                    Package (0x04)
                    {
                        0xFFFF,
                        Zero,
                        LNKD,
                        Zero
                    },

                    Package (0x04)
                    {
                        0xFFFF,
                        One,
                        LNKA,
                        Zero
                    },

                    Package (0x04)
                    {
                        0xFFFF,
                        0x02,
                        LNKB,
                        Zero
                    },

                    Package (0x04)
                    {
                        0xFFFF,
                        0x03,
                        LNKC,
                        Zero
                    },

                    Package (0x04)
                    {
                        0x0001FFFF,
                        Zero,
                        LNKS,
                        Zero
                    },
Context: https://lore.kernel.org/virtualization/20240417145544.38d7b482@imammedo.users.ipa.redhat.com/T/#t

Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20240814115736.1580337-3-ribalda@chromium.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Ricardo Ribalda 2024-08-14 11:56:10 +00:00 committed by Michael S. Tsirkin
parent ae77a40e3c
commit 99cb2c6c7b
1 changed files with 21 additions and 97 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

118
hw/i386/acpi-build.c
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@ -724,120 +724,44 @@ static Aml *aml_pci_pdsm(void)
return method;
}
/**
* build_prt_entry:
* @link_name: link name for PCI route entry
*
* build AML package containing a PCI route entry for @link_name
*/
static Aml *build_prt_entry(const char *link_name)
{
Aml *a_zero = aml_int(0);
Aml *pkg = aml_package(4);
aml_append(pkg, a_zero);
aml_append(pkg, a_zero);
aml_append(pkg, aml_name("%s", link_name));
aml_append(pkg, a_zero);
return pkg;
}
/*
* initialize_route - Initialize the interrupt routing rule
* through a specific LINK:
* if (lnk_idx == idx)
* route using link 'link_name'
*/
static Aml *initialize_route(Aml *route, const char *link_name,
Aml *lnk_idx, int idx)
{
Aml *if_ctx = aml_if(aml_equal(lnk_idx, aml_int(idx)));
Aml *pkg = build_prt_entry(link_name);
aml_append(if_ctx, aml_store(pkg, route));
return if_ctx;
}
/*
* build_prt - Define interrupt rounting rules
* build_prt - Define interrupt routing rules
*
* Returns an array of 128 routes, one for each device,
* based on device location.
* The main goal is to equally distribute the interrupts
* over the 4 existing ACPI links (works only for i440fx).
* The hash function is (slot + pin) & 3 -> "LNK[D|A|B|C]".
* The hash function is: (slot + pin) & 3 -> "LNK[D|A|B|C]".
*
*/
static Aml *build_prt(bool is_pci0_prt)
{
Aml *method, *while_ctx, *pin, *res;
const int nroutes = 128;
Aml *rt_pkg, *method;
int pin;
method = aml_method("_PRT", 0, AML_NOTSERIALIZED);
res = aml_local(0);
pin = aml_local(1);
aml_append(method, aml_store(aml_package(128), res));
aml_append(method, aml_store(aml_int(0), pin));
rt_pkg = aml_varpackage(nroutes);
/* while (pin < 128) */
while_ctx = aml_while(aml_lless(pin, aml_int(128)));
{
Aml *slot = aml_local(2);
Aml *lnk_idx = aml_local(3);
Aml *route = aml_local(4);
for (pin = 0; pin < nroutes; pin++) {
Aml *pkg = aml_package(4);
int slot = pin >> 2;
/* slot = pin >> 2 */
aml_append(while_ctx,
aml_store(aml_shiftright(pin, aml_int(2), NULL), slot));
/* lnk_idx = (slot + pin) & 3 */
aml_append(while_ctx,
aml_store(aml_and(aml_add(pin, slot, NULL), aml_int(3), NULL),
lnk_idx));
/* route[2] = "LNK[D|A|B|C]", selection based on pin % 3 */
aml_append(while_ctx, initialize_route(route, "LNKD", lnk_idx, 0));
if (is_pci0_prt) {
Aml *if_device_1, *if_pin_4, *else_pin_4;
/* device 1 is the power-management device, needs SCI */
if_device_1 = aml_if(aml_equal(lnk_idx, aml_int(1)));
{
if_pin_4 = aml_if(aml_equal(pin, aml_int(4)));
{
aml_append(if_pin_4,
aml_store(build_prt_entry("LNKS"), route));
}
aml_append(if_device_1, if_pin_4);
else_pin_4 = aml_else();
{
aml_append(else_pin_4,
aml_store(build_prt_entry("LNKA"), route));
}
aml_append(if_device_1, else_pin_4);
}
aml_append(while_ctx, if_device_1);
aml_append(pkg, aml_int((slot << 16) | 0xFFFF));
aml_append(pkg, aml_int(pin & 3));
/* device 1 is the power-management device, needs SCI */
if (is_pci0_prt && pin == 4) {
aml_append(pkg, aml_name("%s", "LNKS"));
} else {
aml_append(while_ctx, initialize_route(route, "LNKA", lnk_idx, 1));
static const char link_name[][5] = {"LNKD", "LNKA", "LNKB", "LNKC"};
int hash = (slot + pin) & 3;
aml_append(pkg, aml_name("%s", link_name[hash]));
}
aml_append(while_ctx, initialize_route(route, "LNKB", lnk_idx, 2));
aml_append(while_ctx, initialize_route(route, "LNKC", lnk_idx, 3));
/* route[0] = 0x[slot]FFFF */
aml_append(while_ctx,
aml_store(aml_or(aml_shiftleft(slot, aml_int(16)), aml_int(0xFFFF),
NULL),
aml_index(route, aml_int(0))));
/* route[1] = pin & 3 */
aml_append(while_ctx,
aml_store(aml_and(pin, aml_int(3), NULL),
aml_index(route, aml_int(1))));
/* res[pin] = route */
aml_append(while_ctx, aml_store(route, aml_index(res, pin)));
/* pin++ */
aml_append(while_ctx, aml_increment(pin));
aml_append(pkg, aml_int(0));
aml_append(rt_pkg, pkg);
}
aml_append(method, while_ctx);
/* return res*/
aml_append(method, aml_return(res));
aml_append(method, aml_return(rt_pkg));
return method;
}