qemu-kvm/SOURCES/kvm-hw-i386-acpi-Set-PCAT_COMPAT-bit-only-when-pic-is-no.patch

52 lines
2.0 KiB
Diff

From 7bb1f124413891bc5d2187f12cd19da6e794904b Mon Sep 17 00:00:00 2001
From: Xiaoyao Li <xiaoyao.li@intel.com>
Date: Wed, 3 Apr 2024 10:59:53 -0400
Subject: [PATCH 010/100] hw/i386/acpi: Set PCAT_COMPAT bit only when pic is
not disabled
RH-Author: Paolo Bonzini <pbonzini@redhat.com>
RH-MergeRequest: 245: SEV-SNP support
RH-Jira: RHEL-39544
RH-Acked-by: Thomas Huth <thuth@redhat.com>
RH-Acked-by: Bandan Das <bdas@redhat.com>
RH-Acked-by: Vitaly Kuznetsov <vkuznets@redhat.com>
RH-Commit: [10/91] 62110e4bf52cb3e106c8d2a902bbd31548beba00 (bonzini/rhel-qemu-kvm)
A value 1 of PCAT_COMPAT (bit 0) of MADT.Flags indicates that the system
also has a PC-AT-compatible dual-8259 setup, i.e., the PIC. When PIC
is not enabled (pic=off) for x86 machine, the PCAT_COMPAT bit needs to
be cleared. The PIC probe should then print:
[ 0.155970] Using NULL legacy PIC
However, no such log printed in guest kernel unless PCAT_COMPAT is
cleared.
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Message-ID: <20240403145953.3082491-1-xiaoyao.li@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 292dd287e78e0cbafde9d1522c729349d132d844)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
hw/i386/acpi-common.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/hw/i386/acpi-common.c b/hw/i386/acpi-common.c
index 20f19269da..0cc2919bb8 100644
--- a/hw/i386/acpi-common.c
+++ b/hw/i386/acpi-common.c
@@ -107,7 +107,9 @@ void acpi_build_madt(GArray *table_data, BIOSLinker *linker,
acpi_table_begin(&table, table_data);
/* Local APIC Address */
build_append_int_noprefix(table_data, APIC_DEFAULT_ADDRESS, 4);
- build_append_int_noprefix(table_data, 1 /* PCAT_COMPAT */, 4); /* Flags */
+ /* Flags. bit 0: PCAT_COMPAT */
+ build_append_int_noprefix(table_data,
+ x86ms->pic != ON_OFF_AUTO_OFF ? 1 : 0 , 4);
for (i = 0; i < apic_ids->len; i++) {
pc_madt_cpu_entry(i, apic_ids, table_data, false);
--
2.39.3