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| author | Saurabh Sengar <ssengar@linux.microsoft.com> | 2024-03-03 00:01:36 -0800 |
|---|---|---|
| committer | Wei Liu <wei.liu@kernel.org> | 2024-03-08 23:40:09 +0000 |
| commit | 2b4b90e053a29057fb05ba81acce26bddce8d404 (patch) | |
| tree | 563b6b0c779a3cfbd0da364ae1a6cfadb5158e52 | |
| parent | 0e3f7d120086c8b9d6e1ae0dd4917fc529daa1ca (diff) | |
| download | lwn-2b4b90e053a29057fb05ba81acce26bddce8d404.tar.gz lwn-2b4b90e053a29057fb05ba81acce26bddce8d404.zip | |
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: 3be1bc2fe9d2 ("x86/hyperv: VTL support for Hyper-V")
Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Link: https://lore.kernel.org/r/1709452896-13342-1-git-send-email-ssengar@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <1709452896-13342-1-git-send-email-ssengar@linux.microsoft.com>
| -rw-r--r-- | arch/x86/hyperv/hv_vtl.c | 19 | ||||
| -rw-r--r-- | drivers/hv/Kconfig | 1 |
2 files changed, 16 insertions, 4 deletions
diff --git a/arch/x86/hyperv/hv_vtl.c b/arch/x86/hyperv/hv_vtl.c index 96e6c51515f5..92bd5a55f093 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 +72,9 @@ 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 +201,15 @@ 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 +223,7 @@ 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) diff --git a/drivers/hv/Kconfig b/drivers/hv/Kconfig index 00242107d62e..862c47b191af 100644 --- a/drivers/hv/Kconfig +++ b/drivers/hv/Kconfig @@ -16,6 +16,7 @@ config HYPERV config HYPERV_VTL_MODE bool "Enable Linux to boot in VTL context" depends on X86_64 && HYPERV + depends on SMP default n help Virtual Secure Mode (VSM) is a set of hypervisor capabilities and |