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| author | Boris Ostrovsky <boris.ostrovsky@oracle.com> | 2017-04-24 15:04:53 -0400 |
|---|---|---|
| committer | Juergen Gross <jgross@suse.com> | 2017-05-02 11:18:05 +0200 |
| commit | 84d582d236dc1f9085e741affc72e9ba061a67c2 (patch) | |
| tree | 7d012e4f1739b44c0bb5373a091a6f195c057d82 /arch/x86/pci/xen.c | |
| parent | 5f6a1614fab801834e32b420b60acdc27acfcdec (diff) | |
| download | linux-84d582d236dc1f9085e741affc72e9ba061a67c2.tar.gz linux-84d582d236dc1f9085e741affc72e9ba061a67c2.tar.bz2 linux-84d582d236dc1f9085e741affc72e9ba061a67c2.zip | |
xen: Revert commits da72ff5bfcb0 and 72a9b186292d
Recent discussion (http://marc.info/?l=xen-devel&m=149192184523741)
established that commit 72a9b186292d ("xen: Remove event channel
notification through Xen PCI platform device") (and thus commit
da72ff5bfcb0 ("partially revert "xen: Remove event channel
notification through Xen PCI platform device"")) are unnecessary and,
in fact, prevent HVM guests from booting on Xen releases prior to 4.0
Therefore we revert both of those commits.
The summary of that discussion is below:
Here is the brief summary of the current situation:
Before the offending commit (72a9b186292):
1) INTx does not work because of the reset_watches path.
2) The reset_watches path is only taken if you have Xen > 4.0
3) The Linux Kernel by default will use vector inject if the hypervisor
support. So even INTx does not work no body running the kernel with
Xen > 4.0 would notice. Unless he explicitly disabled this feature
either in the kernel or in Xen (and this can only be disabled by
modifying the code, not user-supported way to do it).
After the offending commit (+ partial revert):
1) INTx is no longer support for HVM (only for PV guests).
2) Any HVM guest The kernel will not boot on Xen < 4.0 which does
not have vector injection support. Since the only other mode
supported is INTx which.
So based on this summary, I think before commit (72a9b186292) we were
in much better position from a user point of view.
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Diffstat (limited to 'arch/x86/pci/xen.c')
| -rw-r--r-- | arch/x86/pci/xen.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c index 292ab0364a89..c4b3646bd04c 100644 --- a/arch/x86/pci/xen.c +++ b/arch/x86/pci/xen.c @@ -447,7 +447,7 @@ void __init xen_msi_init(void) int __init pci_xen_hvm_init(void) { - if (!xen_feature(XENFEAT_hvm_pirqs)) + if (!xen_have_vector_callback || !xen_feature(XENFEAT_hvm_pirqs)) return 0; #ifdef CONFIG_ACPI |