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[92.26.98.202]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-395cb7ebe4bsm16118634f8f.98.2025.03.17.11.40.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 17 Mar 2025 11:40:46 -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: 5772791e-035f-11f0-9aba-95dc52dad729 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=citrix.com; s=google; t=1742236846; x=1742841646; darn=lists.xenproject.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=LQMPdbs5n7jlJF2V8rD6Jm1jdMD2vppH8sg7+sJDxj0=; b=kmG+tQedMJCfJyq7gurSOf3vgUO3WRrE8ZqpyX+nKMra8yw3kHsDzhZV1u7kngNLAz tiySXGXNr2RGKnp7n7xe1OUU+1YBOslKv7CS4RBfuiFQXzdBoRQMxFZtHRuHGm14zVBe 1LS356/Hdh8Bfnu6Uy1w+gFhuMHpGllo/8h7w= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1742236846; x=1742841646; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=LQMPdbs5n7jlJF2V8rD6Jm1jdMD2vppH8sg7+sJDxj0=; b=IfHPl2h49Yvwyec2GzRIHE8pZPGuB5268vBO6lY2bKZLxAVx7cvoz8iu3bxS2EXO2Q IAwlSkV5vx28xOni3cnMpTzJ0M0Fy9pQuiuN6boUXDZZqno7tvIxX96pVq/7u0D/NhJG MqU6NtoFalmUwfHHuc+dYoBoVkDA7CZVkwVuPRTkSWovDRzl6Gry92r6wsYT16ePAnTA UelqvkFoSmq1i5ZP+iCRPIDDZwxD8GLAGGPJxwZRvpvNpZc/72ykXtVklDB3Pm96GI8S ZWhSbCJnbmgn5q1tJMMwSpc7WH6UTpvvlRv7VrHSfcd4nbP9oVXfYzsmuLSHYGIYrMtr 9VFQ== X-Gm-Message-State: AOJu0YxZ9FGU2iSho7bS81Eg5TWFDHOhFXXnFilr9EhltocgLmKMvbMp BOsEFPxsJG9JvMHbjgxM0OJYEaNsCMUG1uJwSXx+YcWXuIRpG+eII96zUx/OGtp8Pa4sPnEIm3T L X-Gm-Gg: ASbGncupuIWES8o32N2YAugqVfE5Ex5yg6ZoGNUYf9cABBzF9WHTCVc0jaShaUZtjlv qv7JRQYu4ZGZHopy30b93Kb4/3/JRExf/jM+egTQ6V3dFJ7R8WfxWDiHd86RNol6eF0XWnXnNhO j+YVsaArbhAIxrQxuYHe0JaevMi9ZQKZcLNVTzRSJmthqhVhswIobPzM+zKHMrOgaw1An5AXsQL uuODrFG4lzOPY4wV0t4/0qe/P3eWOGbI6WVSMfb+NIBayuiqKe/oR7ChwInoaTnoSwmYA4IT8m4 1n5gZMGygII7WLBWJRmm1ymon86KotS7594rd/nHMrTZKPElFYf1XIrI1tlAiSBIXyQtLCfQJEp kXuX55nqB1bdsVsnYRKi/nrJ6 X-Google-Smtp-Source: AGHT+IHRQFYBKXE6JmNFPOa1zBeztYXy+hkF/S3+pV1YDgc/LEN99p50R13UPTMjxjIxuyDcFiNkDA== X-Received: by 2002:a05:6000:381:b0:391:489a:ce12 with SMTP id ffacd0b85a97d-3971daebbc5mr9885741f8f.26.1742236846547; Mon, 17 Mar 2025 11:40:46 -0700 (PDT) From: Andrew Cooper To: Xen-devel Cc: Andrew Cooper , =?utf-8?q?Petr_Bene=C5=A1?= , Jan Beulich , =?utf-8?q?Roger_Pau_Monn=C3=A9?= Subject: [PATCH] x86/emul: Emulate %cr8 accesses Date: Mon, 17 Mar 2025 18:40:44 +0000 Message-Id: <20250317184044.560367-1-andrew.cooper3@citrix.com> X-Mailer: git-send-email 2.39.5 MIME-Version: 1.0 Petr reports: (XEN) MMIO emulation failed (1): d12v1 64bit @ 0010:fffff8057ba7dfbf -> 45 0f 20 c2 ... during introspection. This is MOV %cr8, which is wired up for hvm_mov_{to,from}_cr(); the VMExit fastpaths, but not for the full emulation slowpaths. Wire %cr8 up in hvmemul_{read,write}_cr() too. Reported-by: Petr Beneš Signed-off-by: Andrew Cooper --- CC: Jan Beulich CC: Roger Pau Monné CC: Petr Beneš Like the fastpaths, this depends on all HVM/PVH guests strictly getting an LAPIC, which is guaranteed by XSA-256. There's no such thing as a 64bit CPU without a Local APIC, so no such thing as %cr8 not being TPR. --- xen/arch/x86/hvm/emulate.c | 10 ++++++++++ 1 file changed, 10 insertions(+) base-commit: e7e0d485e993e97b1c816adcfc610e7c7258ce96 diff --git a/xen/arch/x86/hvm/emulate.c b/xen/arch/x86/hvm/emulate.c index dbf6b5543adf..852240b29d74 100644 --- a/xen/arch/x86/hvm/emulate.c +++ b/xen/arch/x86/hvm/emulate.c @@ -2285,6 +2285,11 @@ static int cf_check hvmemul_read_cr( *val = current->arch.hvm.guest_cr[reg]; TRACE(TRC_HVM_CR_READ64, reg, *val, *val >> 32); return X86EMUL_OKAY; + + case 8: + *val = (vlapic_get_reg(vcpu_vlapic(current), APIC_TASKPRI) & 0xf0) >> 4; + return X86EMUL_OKAY; + default: break; } @@ -2325,6 +2330,11 @@ static int cf_check hvmemul_write_cr( rc = hvm_set_cr4(val, true); break; + case 8: + vlapic_set_reg(vcpu_vlapic(current), APIC_TASKPRI, ((val & 0x0f) << 4)); + rc = X86EMUL_OKAY; + break; + default: rc = X86EMUL_UNHANDLEABLE; break;