[ipxe-devel] [PATCH 2/2] [build] Disable TIVOLI_VMM_WORKAROUND in the qemu configuration

[Laszlo Ersek]

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 at redhat.com>
Cc: Gerd Hoffmann <kraxel at redhat.com>
Cc: Greg <rollenwiese at yahoo.com>
Cc: Michael Brown <mcb30 at ipxe.org>
Cc: Michael Prokop <launchpad at michael-prokop.at>
Cc: Paolo Bonzini <pbonzini at redhat.com>
Cc: Peter Pickford <arch at netremedies.ca>
Cc: Radim Krčmář <rkrcmar at 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 at redhat.com>
---
 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 30f60d3f704a..a084497359fe 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
-- 
2.9.2