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| author | Vitaly Kuznetsov <vkuznets@redhat.com> | 2018-07-09 19:40:12 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2018-07-16 11:19:49 +0200 |
| commit | 110d2a7fc39725d2c29d2fede4f34a35a4f98882 (patch) | |
| tree | 4b027ac896d2f113ac2e15fe8cc97115f6577fc8 /arch/x86/hyperv | |
| parent | 0f0caa52cd4a48a44f6cdc77bf83272bbb450727 (diff) | |
| download | linux-0-day-110d2a7fc39725d2c29d2fede4f34a35a4f98882.tar.gz linux-0-day-110d2a7fc39725d2c29d2fede4f34a35a4f98882.tar.xz | |
x86/hyper-v: Check for VP_INVAL in hyperv_flush_tlb_others()
Commit 1268ed0c474a ("x86/hyper-v: Fix the circular dependency in IPI
enlightenment") pre-filled hv_vp_index with VP_INVAL so it is now
(theoretically) possible to observe hv_cpu_number_to_vp_number()
returning VP_INVAL. We need to check for that in hyperv_flush_tlb_others().
Not checking for VP_INVAL on the first call site where we do
if (hv_cpu_number_to_vp_number(cpumask_last(cpus)) >= 64)
goto do_ex_hypercall;
is OK, in case we're eligible for non-ex hypercall we'll catch the
issue later in for_each_cpu() cycle and in case we'll be doing ex-
hypercall cpumask_to_vpset() will fail.
It would be nice to change hv_cpu_number_to_vp_number() return
value's type to 'u32' but this will likely be a bigger change as
all call sites need to be checked first.
Fixes: 1268ed0c474a ("x86/hyper-v: Fix the circular dependency in IPI enlightenment")
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: "Michael Kelley (EOSG)" <Michael.H.Kelley@microsoft.com>
Cc: devel@linuxdriverproject.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lkml.kernel.org/r/20180709174012.17429-3-vkuznets@redhat.com
Diffstat (limited to 'arch/x86/hyperv')
| -rw-r--r-- | arch/x86/hyperv/mmu.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/x86/hyperv/mmu.c b/arch/x86/hyperv/mmu.c index 453d2355cd61d..1147e1fed7fff 100644 --- a/arch/x86/hyperv/mmu.c +++ b/arch/x86/hyperv/mmu.c @@ -111,6 +111,11 @@ static void hyperv_flush_tlb_others(const struct cpumask *cpus, for_each_cpu(cpu, cpus) { vcpu = hv_cpu_number_to_vp_number(cpu); + if (vcpu == VP_INVAL) { + local_irq_restore(flags); + goto do_native; + } + if (vcpu >= 64) goto do_ex_hypercall; |