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authorVitaly Kuznetsov <vkuznets@redhat.com>2018-01-24 14:23:31 +0100
committerThomas Gleixner <tglx@linutronix.de>2018-01-30 23:55:32 +0100
commit89a8f6d4904c8cf3ff8fee9fdaff392a6bbb8bf6 (patch)
tree7b5250243d4901ebfc1122890b2c431d74951e46 /arch
parent72906f38934a49faf4d2d38ea9ae32adcf7d5d0c (diff)
x86/hyperv: Check for required priviliges in hyperv_init()
In hyperv_init() its presumed that it always has access to VP index and hypercall MSRs while according to the specification it should be checked if it's allowed to access the corresponding MSRs before accessing them. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: kvm@vger.kernel.org Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: "Michael Kelley (EOSG)" <Michael.H.Kelley@microsoft.com> Cc: Roman Kagan <rkagan@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: devel@linuxdriverproject.org Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Cathy Avery <cavery@redhat.com> Cc: Mohammed Gamal <mmorsy@redhat.com> Link: https://lkml.kernel.org/r/20180124132337.30138-2-vkuznets@redhat.com
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/hyperv/hv_init.c9
1 files changed, 8 insertions, 1 deletions
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index 189a398290db..21f9d53d9f00 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -110,12 +110,19 @@ static int hv_cpu_init(unsigned int cpu)
*/
void hyperv_init(void)
{
- u64 guest_id;
+ u64 guest_id, required_msrs;
union hv_x64_msr_hypercall_contents hypercall_msr;
if (x86_hyper_type != X86_HYPER_MS_HYPERV)
return;
+ /* Absolutely required MSRs */
+ required_msrs = HV_X64_MSR_HYPERCALL_AVAILABLE |
+ HV_X64_MSR_VP_INDEX_AVAILABLE;
+
+ if ((ms_hyperv.features & required_msrs) != required_msrs)
+ return;
+
/* Allocate percpu VP index */
hv_vp_index = kmalloc_array(num_possible_cpus(), sizeof(*hv_vp_index),
GFP_KERNEL);