Re: [RFC][PATCH 1/2] Make irq0-inti2 override in BIOS configurable from userspace
Hi Beth,
On Thu, Jan 22, 2009 at 10:29:36PM -0600, Beth Kon wrote:
This series of patches (nearly) resolves the irq0-inti2 override issue, and
gets the hpet working on kvm with and
without the in-kernel irqchip (i.e., it disables userspace and in-kernel pit
as needed).
- irq0-inti2
The resolution was to always use the override unless the kernel cannot do
irq routing (i.e., compatibility with old
kernels). So qemu checks whether the kernel is capable of irq routing. If
so, qemu tells kvm to route irq0 to
inti2 via the irq routing interface, and tells bios to add the irq0-inti2
override to the MADT interrupt source
override table, and to the mp table (for the non-acpi case). The only
outstanding problem here is that when I set
acpi=off on the kernel boot line, the boot fails. Apparently linux does not
like the way I implemented the override
for the mp table in rombios32.c. Since I am pressed for time at the moment,
I'm putting this patch set out for comments
in hopes that someone else may immediately see the problem. Otherwise I'll
keep looking into it as time permits.
The mptable is not being initialized as you intented because
irq0override is read from fw cfg after mptable initialization (oops).
Also the kernel irq ack notifiers lack knowledge about the routing
table, assuming identity mapping.
See attached patches (qemu-kvm.c change avoids the creation of two
routing entries for pin 2 pointing to different gsi's, 0 and 2).
RHEL5 guests complain about Invalid checksum, so there's still
something wrong in either acpi or mptable setup. I'll try to look
into this next week if nobody beats me.
BIOS-e820: fffbc000 - 0001 (reserved)
DMI 2.4 present.
ERROR: Invalid checksum
No NUMA configuration found
Great work Beth, thanks!
Index: kvm-userspace.tip/bios/rombios32.c
===
--- kvm-userspace.tip.orig/bios/rombios32.c
+++ kvm-userspace.tip/bios/rombios32.c
@@ -2299,14 +2299,14 @@ void rombios32_init(uint32_t *s3_resume_
if (bios_table_cur_addr != 0) {
+irq0_override_probe();
+
mptable_init();
uuid_probe();
smbios_init();
-irq0_override_probe();
-
if (acpi_enabled)
acpi_bios_init();
Index: kvm-userspace.tip/qemu/qemu-kvm.c
===
--- kvm-userspace.tip.orig/qemu/qemu-kvm.c
+++ kvm-userspace.tip/qemu/qemu-kvm.c
@@ -817,7 +817,7 @@ int kvm_qemu_create_context(void)
for (i = 0; i 24; ++i) {
if (i == 0)
r = kvm_add_irq_route(kvm_context, i, KVM_IRQCHIP_IOAPIC, 2);
-else
+else if (i != 2)
r = kvm_add_irq_route(kvm_context, i, KVM_IRQCHIP_IOAPIC, i);
if (r 0)
return r;
diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c
index 179dcb0..9316037 100644
--- a/arch/x86/kvm/i8259.c
+++ b/arch/x86/kvm/i8259.c
@@ -49,7 +49,8 @@ static void pic_unlock(struct kvm_pic *s)
spin_unlock(s-lock);
while (acks) {
- kvm_notify_acked_irq(kvm, __ffs(acks));
+ kvm_notify_acked_irq(kvm, SELECT_PIC(__ffs(acks)),
+__ffs(acks));
acks = acks - 1;
}
@@ -232,7 +233,7 @@ int kvm_pic_read_irq(struct kvm *kvm)
}
pic_update_irq(s);
pic_unlock(s);
- kvm_notify_acked_irq(kvm, irq);
+ kvm_notify_acked_irq(kvm, SELECT_PIC(irq), irq);
return intno;
}
diff --git a/arch/x86/kvm/irq.h b/arch/x86/kvm/irq.h
index 82579ee..9f59318 100644
--- a/arch/x86/kvm/irq.h
+++ b/arch/x86/kvm/irq.h
@@ -32,6 +32,8 @@
#include lapic.h
#define PIC_NUM_PINS 16
+#define SELECT_PIC(irq) \
+ ((irq) 8 ? KVM_IRQCHIP_PIC_MASTER : KVM_IRQCHIP_PIC_SLAVE)
struct kvm;
struct kvm_vcpu;
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index ce285e0..c03a0a9 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -352,7 +352,7 @@ void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int
irq,
void kvm_fire_mask_notifiers(struct kvm *kvm, int irq, bool mask);
void kvm_set_irq(struct kvm *kvm, int irq_source_id, int irq, int level);
-void kvm_notify_acked_irq(struct kvm *kvm, unsigned gsi);
+void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin);
void kvm_register_irq_ack_notifier(struct kvm *kvm,
struct kvm_irq_ack_notifier *kian);
void kvm_unregister_irq_ack_notifier(struct kvm_irq_ack_notifier *kian);
diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c
index e85a2bc..1c986ac 100644
--- a/virt/kvm/ioapic.c
+++ b/virt/kvm/ioapic.c
@@ -293,20 +293,20 @@ void kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int
irq, int level)
}
}
-static void __kvm_ioapic_update_eoi(struct kvm_ioapic *ioapic, int gsi,
+static void
[RFC][PATCH 1/2] Make irq0-inti2 override in BIOS configurable from userspace
This series of patches (nearly) resolves the irq0-inti2 override issue, and
gets the hpet working on kvm with and
without the in-kernel irqchip (i.e., it disables userspace and in-kernel pit as
needed).
- irq0-inti2
The resolution was to always use the override unless the kernel cannot do irq
routing (i.e., compatibility with old
kernels). So qemu checks whether the kernel is capable of irq routing. If so,
qemu tells kvm to route irq0 to
inti2 via the irq routing interface, and tells bios to add the irq0-inti2
override to the MADT interrupt source
override table, and to the mp table (for the non-acpi case). The only
outstanding problem here is that when I set
acpi=off on the kernel boot line, the boot fails. Apparently linux does not
like the way I implemented the override
for the mp table in rombios32.c. Since I am pressed for time at the moment,
I'm putting this patch set out for comments
in hopes that someone else may immediately see the problem. Otherwise I'll
keep looking into it as time permits.
- hpet
The hpet works with and without in-kernel irqchip. And many thanks to Marcelo
for finding a bios corruption bug that
was the primary source of win2k864 problems. Now the hpet works on linux
(ubuntu 8.0.4), win2k832. On win2k864 it works
with the in-kernel irqchip but is broken (i.e.,black screen) when
-no-kvm-irqchip is specified. Though I found that
it is also broken when I remove these 2 patches, so it appears to have
nothing to do with hpet or irq routing. Needs
more looking into.
Signed-off-by: Beth Kon e...@us.ibm.com
---
bios/Makefile|2 +-
bios/rombios32.c | 40
qemu/hw/apic.c |5 ++---
qemu/hw/fw_cfg.c |1 +
qemu/hw/fw_cfg.h |1 +
qemu/qemu-kvm.c |5 -
qemu/sysemu.h|1 +
qemu/vl.c| 10 --
8 files changed, 54 insertions(+), 11 deletions(-)
diff --git a/bios/Makefile b/bios/Makefile
index 2d1f40d..374d70e 100644
--- a/bios/Makefile
+++ b/bios/Makefile
@@ -48,7 +48,7 @@ LIBS = -lm
RANLIB = ranlib
BCC = bcc
-GCC = gcc $(CFLAGS)
+GCC = gcc $(CFLAGS) -fno-stack-protector
HOST_CC = gcc
AS86 = as86
diff --git a/bios/rombios32.c b/bios/rombios32.c
index 9d2eaaa..84f15fb 100755
--- a/bios/rombios32.c
+++ b/bios/rombios32.c
@@ -443,6 +443,7 @@ uint32_t cpuid_ext_features;
unsigned long ram_size;
uint64_t ram_end;
uint8_t bios_uuid[16];
+uint8_t irq0_override;
#ifdef BX_USE_EBDA_TABLES
unsigned long ebda_cur_addr;
#endif
@@ -475,6 +476,7 @@ void wrmsr_smp(uint32_t index, uint64_t val)
#define QEMU_CFG_SIGNATURE 0x00
#define QEMU_CFG_ID 0x01
#define QEMU_CFG_UUID 0x02
+#define QEMU_CFG_IRQ0_OVERRIDE 0x07
int qemu_cfg_port;
@@ -516,6 +518,18 @@ void uuid_probe(void)
memset(bios_uuid, 0, 16);
}
+void irq0_override_probe(void)
+{
+#ifdef BX_QEMU
+if(qemu_cfg_port) {
+qemu_cfg_select(QEMU_CFG_IRQ0_OVERRIDE);
+qemu_cfg_read(irq0_override, 1);
+return;
+}
+#endif
+memset(irq0_override, 0, 1);
+}
+
void cpu_probe(void)
{
uint32_t eax, ebx, ecx, edx;
@@ -1149,6 +1163,8 @@ static void mptable_init(void)
/* irqs */
for(i = 0; i 16; i++) {
+if (irq0_override i == 2)
+continue;
putb(q, 3); /* entry type = I/O interrupt */
putb(q, 0); /* interrupt type = vectored interrupt */
putb(q, 0); /* flags: po=0, el=0 */
@@ -1156,7 +1172,10 @@ static void mptable_init(void)
putb(q, 0); /* source bus ID = ISA */
putb(q, i); /* source bus IRQ */
putb(q, ioapic_id); /* dest I/O APIC ID */
-putb(q, i); /* dest I/O APIC interrupt in */
+if (irq0_override i == 0)
+putb(q, 2); /* dest I/O APIC interrupt in */
+else
+putb(q, i); /* dest I/O APIC interrupt in */
}
/* patch length */
len = q - mp_config_table;
@@ -1505,6 +1524,11 @@ void acpi_bios_init(void)
sizeof(struct madt_processor_apic) * MAX_CPUS +
sizeof(struct madt_io_apic);
madt = (void *)(addr);
+for (i = 0; i 16; i++)
+if (PCI_ISA_IRQ_MASK (1U i))
+madt_size += sizeof(struct madt_intsrcovr);
+if (irq0_override)
+madt_size += sizeof(struct madt_intsrcovr);
addr += madt_size;
acpi_tables_size = addr - base_addr;
@@ -1594,8 +1618,15 @@ void acpi_bios_init(void)
io_apic-interrupt = cpu_to_le32(0);
intsrcovr = (struct madt_intsrcovr*)(io_apic + 1);
-for ( i = 0; i 16; i++ ) {
-if ( PCI_ISA_IRQ_MASK (1U i) ) {
+for (i = 0; i 16; i++) {
+if (irq0_override i == 0) {
+memset(intsrcovr, 0, sizeof(*intsrcovr));
+intsrcovr-type = APIC_XRUPT_OVERRIDE;
+intsrcovr-length = sizeof(*intsrcovr);
+intsrcovr-source = i;
+intsrcovr-gsi= 2;
+intsrcovr-flags = 0; //conforms
