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Mon, 09 Nov 2020 11:21:43 +0000 Received: from pps.filterd (userp3020.oracle.com [127.0.0.1]) by userp3020.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 0A9BL0o0109323; Mon, 9 Nov 2020 11:21:43 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by userp3020.oracle.com with ESMTP id 34p5bqd06u-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 09 Nov 2020 11:21:43 +0000 Received: from abhmp0018.oracle.com (abhmp0018.oracle.com [141.146.116.24]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 0A9BLf0b014960; Mon, 9 Nov 2020 11:21:41 GMT Received: from linux.home (/92.157.91.83) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Mon, 09 Nov 2020 03:21:41 -0800 From: Alexandre Chartre To: "tglx@linutronix.de"@aserv0122.oracle.com, "mingo@redhat.com"@aserv0122.oracle.com, "bp@alien8.de"@aserv0122.oracle.com, "hpa@zytor.com"@aserv0122.oracle.com, "x86@kernel.org"@aserv0122.oracle.com, "dave.hansen@linux.intel.com"@aserv0122.oracle.com, "luto@kernel.org"@aserv0122.oracle.com, "peterz@infradead.org"@aserv0122.oracle.com, "linux-kernel@vger.kernel.org"@aserv0122.oracle.com, "thomas.lendacky@amd.com"@aserv0122.oracle.com, "jroedel@suse.de"@aserv0122.oracle.com Cc: "konrad.wilk@oracle.com"@aserv0122.oracle.com, "jan.setjeeilers@oracle.com"@aserv0122.oracle.com, "junaids@google.com"@aserv0122.oracle.com, "oweisse@google.com"@aserv0122.oracle.com, "rppt@linux.vnet.ibm.com"@aserv0122.oracle.com, "graf@amazon.de"@aserv0122.oracle.com, "mgross@linux.intel.com"@aserv0122.oracle.com, "kuzuno@gmail.com"@aserv0122.oracle.com, "alexandre.chartre@oracle.com"@aserv0122.oracle.com Subject: [RFC][PATCH 08/24] x86/entry: Add C version of SWAPGS and SWAPGS_UNSAFE_STACK Date: Mon, 9 Nov 2020 12:23:03 +0100 Message-Id: <20201109112319.264511-9-alexandre.chartre@oracle.com> X-Mailer: git-send-email 2.18.4 In-Reply-To: <20201109112319.264511-1-alexandre.chartre@oracle.com> References: <20201109112319.264511-1-alexandre.chartre@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9799 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 malwarescore=0 phishscore=0 spamscore=0 mlxlogscore=999 bulkscore=0 suspectscore=0 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2011090075 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9799 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 bulkscore=0 mlxlogscore=999 mlxscore=0 malwarescore=0 suspectscore=0 lowpriorityscore=0 adultscore=0 phishscore=0 priorityscore=1501 spamscore=0 impostorscore=0 clxscore=1015 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2011090074 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org SWAPGS and SWAPGS_UNSAFE_STACK are assembly macros. Add C versions of these macros (swapgs() and swapgs_unsafe_stack()). Signed-off-by: Alexandre Chartre --- arch/x86/include/asm/paravirt.h | 15 +++++++++++++++ arch/x86/include/asm/paravirt_types.h | 17 ++++++++++++----- 2 files changed, 27 insertions(+), 5 deletions(-) diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h index d25cc6830e89..a4898130b36b 100644 --- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -145,6 +145,21 @@ static inline void __write_cr4(unsigned long x) PVOP_VCALL1(cpu.write_cr4, x); } +static inline void swapgs(void) +{ + PVOP_VCALL0(cpu.swapgs); +} + +/* + * If swapgs is used while the userspace stack is still current, + * there's no way to call a pvop. The PV replacement *must* be + * inlined, or the swapgs instruction must be trapped and emulated. + */ +static inline void swapgs_unsafe_stack(void) +{ + PVOP_VCALL0_ALT(cpu.swapgs, "swapgs"); +} + static inline void arch_safe_halt(void) { PVOP_VCALL0(irq.safe_halt); diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h index 0fad9f61c76a..eea9acc942a3 100644 --- a/arch/x86/include/asm/paravirt_types.h +++ b/arch/x86/include/asm/paravirt_types.h @@ -532,12 +532,12 @@ int paravirt_disable_iospace(void); pre, post, ##__VA_ARGS__) -#define ____PVOP_VCALL(op, clbr, call_clbr, extra_clbr, pre, post, ...) \ +#define ____PVOP_VCALL(op, insn, clbr, call_clbr, extra_clbr, pre, post, ...) \ ({ \ PVOP_VCALL_ARGS; \ PVOP_TEST_NULL(op); \ asm volatile(pre \ - paravirt_alt(PARAVIRT_CALL) \ + paravirt_alt(insn) \ post \ : call_clbr, ASM_CALL_CONSTRAINT \ : paravirt_type(op), \ @@ -547,12 +547,17 @@ int paravirt_disable_iospace(void); }) #define __PVOP_VCALL(op, pre, post, ...) \ - ____PVOP_VCALL(op, CLBR_ANY, PVOP_VCALL_CLOBBERS, \ - VEXTRA_CLOBBERS, \ + ____PVOP_VCALL(op, PARAVIRT_CALL, CLBR_ANY, \ + PVOP_VCALL_CLOBBERS, VEXTRA_CLOBBERS, \ pre, post, ##__VA_ARGS__) +#define __PVOP_VCALL_ALT(op, insn) \ + ____PVOP_VCALL(op, insn, CLBR_ANY, \ + PVOP_VCALL_CLOBBERS, VEXTRA_CLOBBERS, \ + "", "") + #define __PVOP_VCALLEESAVE(op, pre, post, ...) \ - ____PVOP_VCALL(op.func, CLBR_RET_REG, \ + ____PVOP_VCALL(op.func, PARAVIRT_CALL, CLBR_RET_REG, \ PVOP_VCALLEE_CLOBBERS, , \ pre, post, ##__VA_ARGS__) @@ -562,6 +567,8 @@ int paravirt_disable_iospace(void); __PVOP_CALL(rettype, op, "", "") #define PVOP_VCALL0(op) \ __PVOP_VCALL(op, "", "") +#define PVOP_VCALL0_ALT(op, insn) \ + __PVOP_VCALL_ALT(op, insn) #define PVOP_CALLEE0(rettype, op) \ __PVOP_CALLEESAVE(rettype, op, "", "") -- 2.18.4