From b991c67c1d91574ef22336cc3a5944d1e63230c9 Mon Sep 17 00:00:00 2001
From: Laszlo Ersek <lersek@redhat.com>
Date: Thu, 27 Oct 2016 00:13:51 +0200
Subject: [PATCH] [build] Disable TIVOLI_VMM_WORKAROUND in the qemu
 configuration
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This prevents KVM guests from crashing that run iPXE on host CPUs
without "unrestricted_guest" support.

Once KVM gets the FXSAVE / FXRSTOR emulation feature (*), and the
feature becomes widely available to users, we can back out this change
from iPXE.

(*) Already in progress by Radim:

    [PATCH 0/2] KVM: x86: emulate fxsave and fxrstor

    https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1258895.html
    https://www.spinics.net/lists/kernel/msg2370327.html

Cc: Bandan Das <bsd@redhat.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Greg <rollenwiese@yahoo.com>
Cc: Michael Brown <mcb30@ipxe.org>
Cc: Michael Prokop <launchpad@michael-prokop.at>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Pickford <arch@netremedies.ca>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Ref: https://bugs.archlinux.org/task/50778
Ref: https://bugs.launchpad.net/qemu/+bug/1623276
Ref: https://bugzilla.proxmox.com/show_bug.cgi?id=1182
Ref: https://bugzilla.redhat.com/show_bug.cgi?id=1356762
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
---
 src/config/qemu/general.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/config/qemu/general.h b/src/config/qemu/general.h
index 30f60d3f..a0844973 100644
--- a/src/config/qemu/general.h
+++ b/src/config/qemu/general.h
@@ -8,3 +8,8 @@
 
 /* Work around missing EFI_PXE_BASE_CODE_PROTOCOL */
 #define EFI_DOWNGRADE_UX
+
+/* The Tivoli VMM workaround causes a KVM emulation failure on hosts
+ * without unrestricted_guest support
+ */
+#undef TIVOLI_VMM_WORKAROUND