[xen stable-4.16] x86/pvh: do not forward MADT Local APIC NMI structures to dom0

[patchbot@xxxxxxx]

commit 09849cdd251443f22fb2ee07b2aaa7cd45546b5b
Author:     Roger Pau Monné <roger.pau@xxxxxxxxxx>
AuthorDate: Thu Dec 8 10:10:50 2022 +0100
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Thu Dec 8 10:10:50 2022 +0100

    x86/pvh: do not forward MADT Local APIC NMI structures to dom0
    
    Currently Xen will passthrough any Local APIC NMI Structure found in
    the native ACPI MADT table to a PVH dom0.  This is wrong because PVH
    doesn't have access to the physical local APIC, and instead gets an
    emulated local APIC by Xen, that doesn't have the LINT0 or LINT1
    pins wired to anything.  Furthermore the ACPI Processor UIDs used in
    the APIC NMI Structures are likely to not match the ones generated by
    Xen for the Local x2APIC Structures, creating confusion to dom0.
    
    Fix this by removing the logic to passthrough the Local APIC NMI
    Structure for PVH dom0.
    
    Fixes: 1d74282c45 ('x86: setup PVHv2 Dom0 ACPI tables')
    Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
    Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
    master commit: b39e6385250ccef9509af0eab9003ad5c1478842
    master date: 2022-12-02 10:33:40 +0100
---
 xen/arch/x86/hvm/dom0_build.c | 34 +---------------------------------
 1 file changed, 1 insertion(+), 33 deletions(-)

diff --git a/xen/arch/x86/hvm/dom0_build.c b/xen/arch/x86/hvm/dom0_build.c
index 8048987286..862c73830f 100644
--- a/xen/arch/x86/hvm/dom0_build.c
+++ b/xen/arch/x86/hvm/dom0_build.c
@@ -58,9 +58,6 @@
 static unsigned int __initdata acpi_intr_overrides;
 static struct acpi_madt_interrupt_override __initdata *intsrcovr;
 
-static unsigned int __initdata acpi_nmi_sources;
-static struct acpi_madt_nmi_source __initdata *nmisrc;
-
 static unsigned int __initdata order_stats[MAX_ORDER + 1];
 
 static void __init print_order_stats(const struct domain *d)
@@ -761,25 +758,6 @@ static int __init acpi_set_intr_ovr(struct 
acpi_subtable_header *header,
     return 0;
 }
 
-static int __init acpi_count_nmi_src(struct acpi_subtable_header *header,
-                                     const unsigned long end)
-{
-    acpi_nmi_sources++;
-    return 0;
-}
-
-static int __init acpi_set_nmi_src(struct acpi_subtable_header *header,
-                                   const unsigned long end)
-{
-    const struct acpi_madt_nmi_source *src =
-        container_of(header, struct acpi_madt_nmi_source, header);
-
-    *nmisrc = *src;
-    nmisrc++;
-
-    return 0;
-}
-
 static int __init pvh_setup_acpi_madt(struct domain *d, paddr_t *addr)
 {
     struct acpi_table_madt *madt;
@@ -795,16 +773,11 @@ static int __init pvh_setup_acpi_madt(struct domain *d, 
paddr_t *addr)
     acpi_table_parse_madt(ACPI_MADT_TYPE_INTERRUPT_OVERRIDE,
                           acpi_count_intr_ovr, UINT_MAX);
 
-    /* Count number of NMI sources in the MADT. */
-    acpi_table_parse_madt(ACPI_MADT_TYPE_NMI_SOURCE, acpi_count_nmi_src,
-                          UINT_MAX);
-
     max_vcpus = dom0_max_vcpus();
     /* Calculate the size of the crafted MADT. */
     size = sizeof(*madt);
     size += sizeof(*io_apic) * nr_ioapics;
     size += sizeof(*intsrcovr) * acpi_intr_overrides;
-    size += sizeof(*nmisrc) * acpi_nmi_sources;
     size += sizeof(*x2apic) * max_vcpus;
 
     madt = xzalloc_bytes(size);
@@ -860,12 +833,7 @@ static int __init pvh_setup_acpi_madt(struct domain *d, 
paddr_t *addr)
     acpi_table_parse_madt(ACPI_MADT_TYPE_INTERRUPT_OVERRIDE, acpi_set_intr_ovr,
                           acpi_intr_overrides);
 
-    /* Setup NMI sources. */
-    nmisrc = (void *)intsrcovr;
-    acpi_table_parse_madt(ACPI_MADT_TYPE_NMI_SOURCE, acpi_set_nmi_src,
-                          acpi_nmi_sources);
-
-    ASSERT(((void *)nmisrc - (void *)madt) == size);
+    ASSERT(((void *)intsrcovr - (void *)madt) == size);
     madt->header.length = size;
     /*
      * Calling acpi_tb_checksum here is a layering violation, but
--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.16