Xen project Mailing List

Re: [PATCH 3/3] x86: Fix calculation of %dr6/dr7 reserved bits

To: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>

Date: Tue, 29 Aug 2023 16:21:51 +0200

Arc-authentication-results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=suse.com; dmarc=pass action=none header.from=suse.com; dkim=pass header.d=suse.com; arc=none

Arc-message-signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=fqZQyZrY36izFBLb6hlQzKneQ331m94pD6mWUsh/gkA=; b=fyS92K21tMZjhCEX6qDLtJJr4vUggTwUOmeMKR8SB8KKg60ywhCDaimruelgoA4+5DVDrXiKP7WA4ZtxH7fMebmWhq4X3CrzQVPzTsW7K6nuo1+Eu4oT2RZiTDx3mSSM6eOXqGjHPt5g0UPnm4n0AC+DL7EnnXK6H6wfXuJmfIjjBrFieBEFpG8WBGGY+6vmk5TcM0HRYlsgBaiCY7O4/vJ2Vb5HuZHh29pH2xoyPsIFPP8lA0EMFesuaSu+a712lUQiKlCNsDzxQju+19jrWNBspPNku6DV4HrpdmliLJRjfgI5C3oqpM/34Sita+WOv9f2jFb4CXOgI50GOryYJA==

Arc-seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=UCpD/ou05MZ05+LSgAzn5xo1jvapsqqquI9jYnNZUQieox65NoLtFuispmav/dCfMGlrRynrUL1fnKbVcm4NX8OBaN77NiO/HBiPDp5O29HP6apHCO+vm5iBT/LCfp49rpBJh7UWWuVPKUnXn7Vzmd3zSa/wECvT0qV0gkzZvUwDlkl1GlsiiD1l98nHUnCjAoHQbgPAJgqkKXDX1MRduH7QHeEagmC+u3xt7eGr2U4mntDKCIZ7uFjREL+7TzEA20hBfo9lfK2QxLVLpAC7HneHVTwdACD+rhwb3BVjbf6bVDt9JVnqG66F2mU2VPeIDbbB838Z8fPrUNFtBJRPzA==

Authentication-results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=suse.com;

Cc: Jinoh Kang <jinoh.kang.kr@xxxxxxxxx>, Roger Pau Monné <roger.pau@xxxxxxxxxx>, Wei Liu <wl@xxxxxxx>, Xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxxx>

Delivery-date: Tue, 29 Aug 2023 14:22:28 +0000

List-id: Xen developer discussion <xen-devel.lists.xenproject.org>

On 29.08.2023 15:43, Andrew Cooper wrote: > --- a/xen/arch/x86/include/asm/debugreg.h > +++ b/xen/arch/x86/include/asm/debugreg.h > @@ -1,6 +1,7 @@ > #ifndef _X86_DEBUGREG_H > #define _X86_DEBUGREG_H > > +#include <asm/x86-defns.h> > > /* Indicate the register numbers for a number of the specific > debug registers. Registers 0-3 contain the addresses we wish to trap on > */ > @@ -21,7 +22,6 @@ > #define DR_STEP (0x4000) /* single-step */ > #define DR_SWITCH (0x8000) /* task switch */ > #define DR_NOT_RTM (0x10000) /* clear: #BP inside RTM region */ > -#define DR_STATUS_RESERVED_ZERO (~0xffffefffUL) /* Reserved, read as zero */ As you're dropping constants from here, how about the others? Especially DR_NOT_RTM would be nice to go away as well (I don't really like its name), yet DR_SWITCH looks to also be unused. > --- a/xen/arch/x86/include/asm/x86-defns.h > +++ b/xen/arch/x86/include/asm/x86-defns.h > @@ -102,13 +102,30 @@ > > /* > * Debug status flags in DR6. > + * > + * For backwards compatibility, status flags which overlap with > + * X86_DR6_DEFAULT have inverted polarity. > */ > -#define X86_DR6_DEFAULT 0xffff0ff0 /* Default %dr6 value. */ > +#define X86_DR6_B0 (_AC(1, UL) << 0) /* Breakpoint 0 > */ > +#define X86_DR6_B1 (_AC(1, UL) << 1) /* Breakpoint 1 > */ > +#define X86_DR6_B2 (_AC(1, UL) << 2) /* Breakpoint 2 > */ > +#define X86_DR6_B3 (_AC(1, UL) << 3) /* Breakpoint 3 > */ > +#define X86_DR6_BLD (_AC(1, UL) << 11) /* BusLock detect (INV) > */ > +#define X86_DR6_BD (_AC(1, UL) << 13) /* %dr access > */ > +#define X86_DR6_BS (_AC(1, UL) << 14) /* Single step > */ > +#define X86_DR6_BT (_AC(1, UL) << 15) /* Task switch > */ > +#define X86_DR6_RTM (_AC(1, UL) << 16) /* #DB/#BP in RTM > region (INV) */ > + > +#define X86_DR6_ZEROS _AC(0x00010000, UL) /* %dr6 bits forced to > 0 */ 0x00001000? Jan

©2013 Xen Project, A Linux Foundation Collaborative Project. All Rights Reserved.
Linux Foundation is a registered trademark of The Linux Foundation.
Xen Project is a trademark of The Linux Foundation.