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[92.178.7.112]) by smtp.gmail.com with UTF8SMTPSA id 5b1f17b1804b1-447f38142f1sm264813715e9.31.2025.05.27.03.59.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 27 May 2025 03:59:24 -0700 (PDT) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: a4eda8ae-3ae9-11f0-b894-0df219b8e170 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=citrix.com; s=google; t=1748343565; x=1748948365; darn=lists.xenproject.org; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date:from:to :cc:subject:date:message-id:reply-to; bh=h29etSjYCith9Rt5c0e0WrcOLkdV6ZSMP06fnHdPpL4=; b=goMv7xAZEp2Naixd32ZF6IDWG9JKaSQY7nZBf6eeKhZZNiBotryLlidlze/VFGlpBG 9q1ElIYfRfTGTXv5WIL6UuBqizB2hWvJX5/tNk400+V+eFJBt/RM4qRbx/mS0zBJ3LeB WMNq+x8BCyRtqUZ4R5qTfQ6A6mSVlZClhPT1w= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1748343565; x=1748948365; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=h29etSjYCith9Rt5c0e0WrcOLkdV6ZSMP06fnHdPpL4=; b=Kse17QXrtnAJcbT/4+nNKXj/x5x9vRixn1uYJv8JHU7FDbeVu6PE7VSPCa9VK5mwR2 GbCq98YhLSoz93zwgDmFAfmw7zebS8hntvpx9usz7rrKSVTUjXVbEk4WSm4HoaAE+xCw 8l3l5D87J7qELMyb1rx6Gvdz6lLXE1pFKhbOTVaUgguwWv0PuYBhDHFfqvOuiaPS7fJb tBoginfkku7JUPHGk0dKibIdpyK+ayMuECWI5aCiVFsmbh3vEufqsxMlqWJDrDFcGEp7 hEa+Jk8dw4fy5EAxfhwM0+/6N4m8llwon3hvBKVZ068nWXoM/PCfsBuvvos2NI+UGwQm VRoA== X-Gm-Message-State: AOJu0YyruyejfAVpnXyxKzWlohgcrnzF3Wsd6KAeJrQ8K2v7hUsfhT8V ul0K0ewB9FYSLejcuwWKn6Dkl8Z0Q2dIgmyY2Gtu1nwKFFFtli7/0G6ykTyQPIiJESw= X-Gm-Gg: ASbGncs5W663Dcs4dPeK46SdsG645aWYx9PyzJBbwQM4Hcjy/QwmDpByAwv3XRsqlkl UA9JLQDRyHMPI8MMaBON8DQjT6T7xEw71trOrtRQHoDfJCnw9hsLo8yBLy11xJ8i8ah7GQUhD6Z AQif+c5JhZKu/0UgCymfNSxEqZOWYNKj6+aDHGrb8tJCKwUtRV5yhfr9u/crXKd0P6hz40fmmQQ D0pQYuk3iiJIA997KlPGRgOlSVLE92bAkXopmX7lcqf+lXVe1tbhIa/MNSwBCHjPQ+/1d1nMolr VWQkAm+YBusQHpCGcLvu4y/q2MmC4/JuRnWabtfW1kZA4ILCcNIe5iDKDz+f/fo71XrBTpCtVAl KaHHG3hvJEOtAVlLOPc/L8GhA X-Google-Smtp-Source: AGHT+IEKuiuhECiy38BXHjHEquj1+nXtx9Zw7dyv3TzAo0XzE968/F4NksSqH+zi9ZhjBTz0iGE8yw== X-Received: by 2002:a05:6000:4012:b0:3a4:e238:6496 with SMTP id ffacd0b85a97d-3a4e5e9e265mr103570f8f.18.1748343564908; Tue, 27 May 2025 03:59:24 -0700 (PDT) Date: Tue, 27 May 2025 12:59:23 +0200 From: Roger Pau =?utf-8?B?TW9ubsOp?= To: Andrew Cooper Cc: Xen-devel , Manuel Bouyer , Jan Beulich Subject: Re: [PATCH] x86/pv: Fix breakpoint reporting Message-ID: References: <20250526205302.997387-1-andrew.cooper3@citrix.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20250526205302.997387-1-andrew.cooper3@citrix.com> On Mon, May 26, 2025 at 09:53:02PM +0100, Andrew Cooper wrote: > x86_merge_dr6() is not a no-op when 0 is passed in; it will discard the > previously latched breakpoint bits. > > The combination of do_debug()'s manual call to x86_merge_dr6() for external > debuggers, and pv_inject_DB() calling pv_inject_event(), results in two > x86_merge_dr6() calls. > > Feed the same pending_dbg in the second time. This makes pv_inject_event()'s > update of dr6 effectively a no-op, retaining the correct breakpoint bits. > > Fixes: db39fa4b27ea ("x86/pv: Fix merging of new status bits into %dr6") > Reported-by: Manuel Bouyer > Signed-off-by: Andrew Cooper Acked-by: Roger Pau Monné Thanks, Roger.