Hi Sasha,
The patch picked up for the stable tree will need this bit
"[PATCH v6 3/5] hyperv: Enable the hypercall output page for the VTL mode"
https://lore.kernel.org/linux-hyperv/20250108222138.1623703-4-romank@xxxxxxxxxxxxxxxxxxx/
On 1/28/2025 9:53 AM, Sasha Levin wrote:
From: Roman Kisel <romank@xxxxxxxxxxxxxxxxxxx>
[ 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/hypercall-interface
[2] https://github.com/MicrosoftDocs/Virtualization-Documentation/tree/main/tlfs
Reported-by: Michael Kelley <mhklinux@xxxxxxxxxxx>
Closes: https://lore.kernel.org/lkml/SN6PR02MB4157B98CD34781CC87A9D921D40D2@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/
Signed-off-by: Roman Kisel <romank@xxxxxxxxxxxxxxxxxxx>
Reviewed-by: Easwar Hariharan <eahariha@xxxxxxxxxxxxxxxxxxx>
Reviewed-by: Nuno Das Neves <nunodasneves@xxxxxxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20250108222138.1623703-6-romank@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Wei Liu <wei.liu@xxxxxxxxxx>
Message-ID: <20250108222138.1623703-6-romank@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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);
--
Thank you,
Roman
