From: Saurabh Sengar <ssengar@linux.microsoft.com>
To: kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org,
decui@microsoft.com, tglx@linutronix.de, mingo@redhat.com,
bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org,
hpa@zytor.com, dwmw@amazon.co.uk, peterz@infradead.org,
linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: ssengar@microsoft.com
Subject: [PATCH v2] x86/hyperv: Use per cpu initial stack for vtl context
Date: Thu, 1 Feb 2024 23:12:37 -0800 [thread overview]
Message-ID: <1706857957-13857-1-git-send-email-ssengar@linux.microsoft.com> (raw)
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@linux.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
next reply other threads:[~2024-02-02 7:12 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-02 7:12 Saurabh Sengar [this message]
2024-02-05 16:36 ` [PATCH v2] x86/hyperv: Use per cpu initial stack for vtl context Michael Kelley
2024-03-01 9:26 ` Wei Liu
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1706857957-13857-1-git-send-email-ssengar@linux.microsoft.com \
--to=ssengar@linux.microsoft.com \
--cc=bp@alien8.de \
--cc=dave.hansen@linux.intel.com \
--cc=decui@microsoft.com \
--cc=dwmw@amazon.co.uk \
--cc=haiyangz@microsoft.com \
--cc=hpa@zytor.com \
--cc=kys@microsoft.com \
--cc=linux-hyperv@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=ssengar@microsoft.com \
--cc=tglx@linutronix.de \
--cc=wei.liu@kernel.org \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).