git: 0875f3cd74b2 - main - Revert "x86: Enable Intel DMAR by default"

From: Ed Maste <emaste_at_FreeBSD.org>
Date: Tue, 20 Aug 2024 15:50:01 UTC
The branch main has been updated by emaste:

URL: https://cgit.FreeBSD.org/src/commit/?id=0875f3cd74b2f305e82bff4e640c89f891ca84f8

commit 0875f3cd74b2f305e82bff4e640c89f891ca84f8
Author:     Ed Maste <emaste@FreeBSD.org>
AuthorDate: 2024-08-20 15:43:11 +0000
Commit:     Ed Maste <emaste@FreeBSD.org>
CommitDate: 2024-08-20 15:49:25 +0000

    Revert "x86: Enable Intel DMAR by default"
    
    A number of people have reported panics with it enabled by default,
    possibly due to broken ACPI tables, which we do not handle well. D46382
    is a potential fix for this issue.
    
    Additionally DMAR is currently not compatible with bhyve passthrough
    (see comment #10 in PR280817), with a draft patch to address that in
    D25672.
    
    Revert to disabling DMAR by default pending the resolution of those two
    issues.
    
    This reverts commit 3192fc30230ae432b80cca783abc2dbea9d3f383.
    
    PR:             280817
    Sponsored by:   The FreeBSD Foundation
---
 sys/x86/iommu/intel_drv.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/sys/x86/iommu/intel_drv.c b/sys/x86/iommu/intel_drv.c
index 9401892aa9d6..0b25620114cd 100644
--- a/sys/x86/iommu/intel_drv.c
+++ b/sys/x86/iommu/intel_drv.c
@@ -159,8 +159,7 @@ dmar_count_iter(ACPI_DMAR_HEADER *dmarh, void *arg)
 
 int dmar_rmrr_enable = 1;
 
-static int dmar_enable = 1;
-
+static int dmar_enable = 0;
 static void
 dmar_identify(driver_t *driver, device_t parent)
 {