From: Roman Kisel romank@linux.microsoft.com
[ Upstream commit f285d995743269aa9f893e5e9a1065604137c1f6 ]
The Top-Level Functional Specification for Hyper-V, Section 3.6 [1, 2], disallows overlapping of the input and output hypercall areas, and hv_vtl_apicid_to_vp_id() overlaps them.
Use the output hypercall page of the current vCPU for the hypercall.
[1] https://learn.microsoft.com/en-us/virtualization/hyper-v-on-windows/tlfs/hyp... [2] https://github.com/MicrosoftDocs/Virtualization-Documentation/tree/main/tlfs
Reported-by: Michael Kelley mhklinux@outlook.com Closes: https://lore.kernel.org/lkml/SN6PR02MB4157B98CD34781CC87A9D921D40D2@SN6PR02M... Signed-off-by: Roman Kisel romank@linux.microsoft.com Reviewed-by: Easwar Hariharan eahariha@linux.microsoft.com Reviewed-by: Nuno Das Neves nunodasneves@linux.microsoft.com Link: https://lore.kernel.org/r/20250108222138.1623703-6-romank@linux.microsoft.co... Signed-off-by: Wei Liu wei.liu@kernel.org Message-ID: 20250108222138.1623703-6-romank@linux.microsoft.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/hyperv/hv_vtl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/hyperv/hv_vtl.c b/arch/x86/hyperv/hv_vtl.c index 04775346369c5..4e1b1e3b56584 100644 --- a/arch/x86/hyperv/hv_vtl.c +++ b/arch/x86/hyperv/hv_vtl.c @@ -189,7 +189,7 @@ static int hv_vtl_apicid_to_vp_id(u32 apic_id) input->partition_id = HV_PARTITION_ID_SELF; input->apic_ids[0] = apic_id;
- output = (u32 *)input; + output = *this_cpu_ptr(hyperv_pcpu_output_arg);
control = HV_HYPERCALL_REP_COMP_1 | HVCALL_GET_VP_ID_FROM_APIC_ID; status = hv_do_hypercall(control, input, output);