From: Xin Li <xin3.li@intel.com>
To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org
Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org,
andrew.cooper3@citrix.com, seanjc@google.com,
pbonzini@redhat.com, ravi.v.shankar@intel.com
Subject: [PATCH v5 27/34] x86/fred: allow single-step trap and NMI when starting a new thread
Date: Mon, 6 Mar 2023 18:39:39 -0800 [thread overview]
Message-ID: <20230307023946.14516-28-xin3.li@intel.com> (raw)
In-Reply-To: <20230307023946.14516-1-xin3.li@intel.com>
From: "H. Peter Anvin (Intel)" <hpa@zytor.com>
Allow single-step trap and NMI when starting a new thread, thus once
the new thread returns to ring3, single-step trap and NMI are both
enabled immediately.
High-order 48 bits above the lowest 16 bit CS are discarded by the
legacy IRET instruction, thus can be set unconditionally, even when
FRED is not enabled.
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Tested-by: Shan Kang <shan.kang@intel.com>
Signed-off-by: Xin Li <xin3.li@intel.com>
---
arch/x86/include/asm/fred.h | 11 +++++++++++
arch/x86/kernel/process_64.c | 13 +++++++------
2 files changed, 18 insertions(+), 6 deletions(-)
diff --git a/arch/x86/include/asm/fred.h b/arch/x86/include/asm/fred.h
index cd974edc8e8a..12449448e9bf 100644
--- a/arch/x86/include/asm/fred.h
+++ b/arch/x86/include/asm/fred.h
@@ -52,6 +52,14 @@
#define FRED_CSL_ALLOW_SINGLE_STEP _BITUL(25)
#define FRED_CSL_INTERRUPT_SHADOW _BITUL(24)
+/*
+ * High-order 48 bits above the lowest 16 bit CS are discarded by the
+ * legacy IRET instruction, thus can be set unconditionally, even when
+ * FRED is not enabled.
+ */
+#define CSL_PROCESS_START \
+ (FRED_CSL_ENABLE_NMI | FRED_CSL_ALLOW_SINGLE_STEP)
+
#ifndef __ASSEMBLY__
#include <linux/kernel.h>
@@ -115,6 +123,9 @@ void fred_setup_apic(void);
#else
#define cpu_init_fred_exceptions() BUG()
#define fred_setup_apic() BUG()
+
+#define CSL_PROCESS_START 0
+
#endif /* CONFIG_X86_FRED */
#endif /* ASM_X86_FRED_H */
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index ff6594dbea4a..b23850352e7d 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -55,6 +55,7 @@
#include <asm/resctrl.h>
#include <asm/unistd.h>
#include <asm/fsgsbase.h>
+#include <asm/fred.h>
#ifdef CONFIG_IA32_EMULATION
/* Not included via unistd.h */
#include <asm/unistd_32_ia32.h>
@@ -506,7 +507,7 @@ void x86_gsbase_write_task(struct task_struct *task, unsigned long gsbase)
static void
start_thread_common(struct pt_regs *regs, unsigned long new_ip,
unsigned long new_sp,
- unsigned int _cs, unsigned int _ss, unsigned int _ds)
+ u16 _cs, u16 _ss, u16 _ds)
{
WARN_ON_ONCE(regs != current_pt_regs());
@@ -521,11 +522,11 @@ start_thread_common(struct pt_regs *regs, unsigned long new_ip,
loadsegment(ds, _ds);
load_gs_index(0);
- regs->ip = new_ip;
- regs->sp = new_sp;
- regs->cs = _cs;
- regs->ss = _ss;
- regs->flags = X86_EFLAGS_IF;
+ regs->ip = new_ip;
+ regs->sp = new_sp;
+ regs->csx = _cs | CSL_PROCESS_START;
+ regs->ssx = _ss;
+ regs->flags = X86_EFLAGS_IF | X86_EFLAGS_FIXED;
}
void
--
2.34.1
next prev parent reply other threads:[~2023-03-07 3:07 UTC|newest]
Thread overview: 80+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-07 2:39 [PATCH v5 00/34] x86: enable FRED for x86-64 Xin Li
2023-03-07 2:39 ` [PATCH v5 01/34] x86/traps: let common_interrupt() handle IRQ_MOVE_CLEANUP_VECTOR Xin Li
2023-03-07 2:39 ` [PATCH v5 02/34] x86/traps: add a system interrupt table for system interrupt dispatch Xin Li
2023-03-07 2:39 ` [PATCH v5 03/34] x86/traps: add install_system_interrupt_handler() Xin Li
2023-03-07 2:39 ` [PATCH v5 04/34] x86/traps: add external_interrupt() to dispatch external interrupts Xin Li
2023-03-20 15:36 ` Peter Zijlstra
2023-03-20 17:42 ` Peter Zijlstra
2023-03-20 23:47 ` Li, Xin3
2023-03-20 17:53 ` Li, Xin3
2023-03-07 2:39 ` [PATCH v5 05/34] x86/traps: export external_interrupt() for VMX IRQ reinjection Xin Li
2023-03-22 17:52 ` Sean Christopherson
2023-03-22 22:38 ` Li, Xin3
2023-03-07 2:39 ` [PATCH v5 06/34] x86/cpufeature: add the cpu feature bit for FRED Xin Li
2023-03-07 2:39 ` [PATCH v5 07/34] x86/opcode: add ERETU, ERETS instructions to x86-opcode-map Xin Li
2023-03-07 2:39 ` [PATCH v5 08/34] x86/objtool: teach objtool about ERETU and ERETS Xin Li
2023-03-07 2:39 ` [PATCH v5 09/34] x86/cpu: add X86_CR4_FRED macro Xin Li
2023-03-07 2:39 ` [PATCH v5 10/34] x86/fred: add Kconfig option for FRED (CONFIG_X86_FRED) Xin Li
2023-03-07 2:39 ` [PATCH v5 11/34] x86/fred: if CONFIG_X86_FRED is disabled, disable FRED support Xin Li
2023-03-07 2:39 ` [PATCH v5 12/34] x86/cpu: add MSR numbers for FRED configuration Xin Li
2023-03-07 2:39 ` [PATCH v5 13/34] x86/fred: header file for event types Xin Li
2023-03-07 2:39 ` [PATCH v5 14/34] x86/fred: header file with FRED definitions Xin Li
2023-03-07 2:39 ` [PATCH v5 15/34] x86/fred: make unions for the cs and ss fields in struct pt_regs Xin Li
2023-03-07 2:39 ` [PATCH v5 16/34] x86/fred: reserve space for the FRED stack frame Xin Li
2023-03-07 2:39 ` [PATCH v5 17/34] x86/fred: add a page fault entry stub for FRED Xin Li
2023-03-07 2:39 ` [PATCH v5 18/34] x86/fred: add a debug " Xin Li
2023-03-07 2:39 ` [PATCH v5 19/34] x86/fred: add a NMI " Xin Li
2023-03-07 2:39 ` [PATCH v5 20/34] x86/fred: add a machine check " Xin Li
2023-03-20 16:00 ` Peter Zijlstra
2023-03-21 0:04 ` Li, Xin3
2023-03-21 8:59 ` Peter Zijlstra
2023-03-21 16:38 ` Li, Xin3
2023-03-07 2:39 ` [PATCH v5 21/34] x86/fred: FRED entry/exit and dispatch code Xin Li
2023-03-07 2:39 ` [PATCH v5 22/34] x86/fred: FRED initialization code Xin Li
2023-03-17 13:35 ` Lai Jiangshan
2023-03-17 21:32 ` H. Peter Anvin
2023-03-18 6:33 ` Lai Jiangshan
2023-03-20 16:49 ` Peter Zijlstra
2023-03-21 0:12 ` Li, Xin3
2023-03-21 1:02 ` andrew.cooper3
2023-03-21 7:49 ` Li, Xin3
2023-03-22 16:29 ` Dave Hansen
2023-03-22 2:22 ` Li, Xin3
2023-03-22 4:01 ` Dave Hansen
2023-03-22 5:40 ` Li, Xin3
2023-03-22 18:25 ` andrew.cooper3
2023-03-20 16:44 ` Peter Zijlstra
2023-03-21 0:13 ` Li, Xin3
2023-03-07 2:39 ` [PATCH v5 23/34] x86/fred: update MSR_IA32_FRED_RSP0 during task switch Xin Li
2023-03-20 16:52 ` Peter Zijlstra
2023-03-20 23:54 ` Li, Xin3
2023-03-07 2:39 ` [PATCH v5 24/34] x86/fred: let ret_from_fork() jmp to fred_exit_user when FRED is enabled Xin Li
2023-03-07 2:39 ` [PATCH v5 25/34] x86/fred: disallow the swapgs instruction " Xin Li
2023-03-20 16:54 ` Peter Zijlstra
2023-03-20 17:58 ` Li, Xin3
2023-03-07 2:39 ` [PATCH v5 26/34] x86/fred: no ESPFIX needed " Xin Li
2023-03-07 2:39 ` Xin Li [this message]
2023-03-07 2:39 ` [PATCH v5 28/34] x86/fred: fixup fault on ERETU by jumping to fred_entrypoint_user Xin Li
2023-03-17 9:39 ` Lai Jiangshan
2023-03-17 9:55 ` andrew.cooper3
2023-03-17 13:02 ` Lai Jiangshan
2023-03-17 21:23 ` H. Peter Anvin
2023-03-17 21:00 ` H. Peter Anvin
2023-03-18 7:55 ` Li, Xin3
2023-03-07 2:39 ` [PATCH v5 29/34] x86/ia32: do not modify the DPL bits for a null selector Xin Li
2023-03-07 2:39 ` [PATCH v5 30/34] x86/fred: allow FRED systems to use interrupt vectors 0x10-0x1f Xin Li
2023-03-07 2:39 ` [PATCH v5 31/34] x86/fred: allow dynamic stack frame size Xin Li
2023-03-07 2:39 ` [PATCH v5 32/34] x86/fred: disable FRED by default in its early stage Xin Li
2023-03-07 2:39 ` [PATCH v5 33/34] KVM: x86/vmx: call external_interrupt() to handle IRQ in IRQ caused VM exits Xin Li
2023-03-22 17:57 ` Sean Christopherson
2023-03-07 2:39 ` [PATCH v5 34/34] KVM: x86/vmx: execute "int $2" to handle NMI in NMI caused VM exits when FRED is enabled Xin Li
2023-03-07 22:00 ` Li, Xin3
2023-03-22 17:49 ` Sean Christopherson
2023-03-22 23:03 ` andrew.cooper3
2023-03-22 23:42 ` Sean Christopherson
2023-03-23 0:26 ` Li, Xin3
2023-03-24 17:45 ` Li, Xin3
2023-03-22 23:43 ` Li, Xin3
2023-03-11 9:58 ` [PATCH v5 00/34] x86: enable FRED for x86-64 Kang, Shan
2023-03-11 21:29 ` Li, Xin3
2023-03-20 7:40 ` Kang, Shan
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=20230307023946.14516-28-xin3.li@intel.com \
--to=xin3.li@intel.com \
--cc=andrew.cooper3@citrix.com \
--cc=bp@alien8.de \
--cc=dave.hansen@linux.intel.com \
--cc=hpa@zytor.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=pbonzini@redhat.com \
--cc=peterz@infradead.org \
--cc=ravi.v.shankar@intel.com \
--cc=seanjc@google.com \
--cc=tglx@linutronix.de \
--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 NNTP newsgroup(s).