[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Date: Thu, 1 Feb 2024 23:12:37 -0800
From: Saurabh Sengar <ssengar@...ux.microsoft.com>
To: kys@...rosoft.com,
haiyangz@...rosoft.com,
wei.liu@...nel.org,
decui@...rosoft.com,
tglx@...utronix.de,
mingo@...hat.com,
bp@...en8.de,
dave.hansen@...ux.intel.com,
x86@...nel.org,
hpa@...or.com,
dwmw@...zon.co.uk,
peterz@...radead.org,
linux-hyperv@...r.kernel.org,
linux-kernel@...r.kernel.org
Cc: ssengar@...rosoft.com
Subject: [PATCH v2] x86/hyperv: Use per cpu initial stack for vtl context
Currently, the secondary CPUs in Hyper-V VTL context lack support for
parallel startup. Therefore, relying on the single initial_stack fetched
from the current task structure suffices for all vCPUs.
However, common initial_stack risks stack corruption when parallel startup
is enabled. In order to facilitate parallel startup, use the initial_stack
from the per CPU idle thread instead of the current task.
Fixes: 18415f33e2ac ("cpu/hotplug: Allow "parallel" bringup up to CPUHP_BP_KICK_AP_STATE")
Signed-off-by: Saurabh Sengar <ssengar@...ux.microsoft.com>
---
arch/x86/hyperv/hv_vtl.c | 18 ++++++++++++++----
1 file changed, 14 insertions(+), 4 deletions(-)
diff --git a/arch/x86/hyperv/hv_vtl.c b/arch/x86/hyperv/hv_vtl.c
index 96e6c51515f5..b0ab724def17 100644
--- a/arch/x86/hyperv/hv_vtl.c
+++ b/arch/x86/hyperv/hv_vtl.c
@@ -12,6 +12,7 @@
#include <asm/i8259.h>
#include <asm/mshyperv.h>
#include <asm/realmode.h>
+#include <../kernel/smpboot.h>
extern struct boot_params boot_params;
static struct real_mode_header hv_vtl_real_mode_header;
@@ -57,7 +58,7 @@ static void hv_vtl_ap_entry(void)
((secondary_startup_64_fn)secondary_startup_64)(&boot_params, &boot_params);
}
-static int hv_vtl_bringup_vcpu(u32 target_vp_index, u64 eip_ignored)
+static int hv_vtl_bringup_vcpu(u32 target_vp_index, int cpu, u64 eip_ignored)
{
u64 status;
int ret = 0;
@@ -71,7 +72,8 @@ static int hv_vtl_bringup_vcpu(u32 target_vp_index, u64 eip_ignored)
struct ldttss_desc *ldt;
struct desc_struct *gdt;
- u64 rsp = current->thread.sp;
+ struct task_struct *idle = idle_thread_get(cpu);
+ u64 rsp = (unsigned long)idle->thread.sp;
u64 rip = (u64)&hv_vtl_ap_entry;
native_store_gdt(&gdt_ptr);
@@ -198,7 +200,15 @@ static int hv_vtl_apicid_to_vp_id(u32 apic_id)
static int hv_vtl_wakeup_secondary_cpu(u32 apicid, unsigned long start_eip)
{
- int vp_id;
+ int vp_id, cpu;
+
+ /* Find the logical CPU for the APIC ID */
+ for_each_present_cpu(cpu) {
+ if (arch_match_cpu_phys_id(cpu, apicid))
+ break;
+ }
+ if (cpu >= nr_cpu_ids)
+ return -EINVAL;
pr_debug("Bringing up CPU with APIC ID %d in VTL2...\n", apicid);
vp_id = hv_vtl_apicid_to_vp_id(apicid);
@@ -212,7 +222,7 @@ static int hv_vtl_wakeup_secondary_cpu(u32 apicid, unsigned long start_eip)
return -EINVAL;
}
- return hv_vtl_bringup_vcpu(vp_id, start_eip);
+ return hv_vtl_bringup_vcpu(vp_id, cpu, start_eip);
}
int __init hv_vtl_early_init(void)
--
2.34.1
Powered by blists - more mailing lists