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AJvYcCUbZuzbbts5+032pktkrNlxpT52eL/xbrfeizXwcQ1uXrVeTpGDbgWpDzYe1jsWRITFFGAfAchtItVy@lists.linux.dev X-Gm-Message-State: AOJu0Yw+hY3SeB96Nm16p83yLp4kjQ45chPoyYEv7enly4evt02oYvX3 ysynM4J4ZPvgsoNNTlcXSoh1rTyS7onvyLtRnCz9oKdGMXsnVRfj8HGG/xHCMJvRL4Ser4/iqn4 gokI/WJzFyNWmCqMsgg== X-Google-Smtp-Source: AGHT+IH/8YsBcP5uZYl0bmlmhw3cSkjvn5V2r10re47N885FbaitMXwjoVcr1y27PxvOM4eurK+/YRXaGJnRVEqq X-Received: from pfbei26.prod.google.com ([2002:a05:6a00:80da:b0:730:b665:d832]) (user=vannapurve job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a00:3d0a:b0:730:888a:251d with SMTP id d2e1a72fcca58-73426d9ee22mr716372b3a.20.1740086191802; Thu, 20 Feb 2025 13:16:31 -0800 (PST) Date: Thu, 20 Feb 2025 21:16:24 +0000 Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.48.1.601.g30ceb7b040-goog Message-ID: <20250220211628.1832258-1-vannapurve@google.com> Subject: [PATCH V5 0/4] x86/tdx: Fix HLT logic execution for TDX VMs From: Vishal Annapurve To: x86@kernel.org, linux-kernel@vger.kernel.org, linux-coco@lists.linux.dev, virtualization@lists.linux.dev Cc: pbonzini@redhat.com, seanjc@google.com, erdemaktas@google.com, ackerleytng@google.com, jxgao@google.com, sagis@google.com, oupton@google.com, pgonda@google.com, kirill@shutemov.name, dave.hansen@linux.intel.com, chao.p.peng@linux.intel.com, isaku.yamahata@gmail.com, sathyanarayanan.kuppuswamy@linux.intel.com, jgross@suse.com, ajay.kaher@broadcom.com, alexey.amakhalov@broadcom.com, Vishal Annapurve Content-Type: text/plain; charset="UTF-8" Direct HLT instruction execution causes #VEs for TDX VMs which is routed to hypervisor via TDCALL. safe_halt() routines execute HLT in STI-shadow so IRQs need to remain disabled until the TDCALL to ensure that pending IRQs are correctly treated as wake events. So "sti;hlt" sequence needs to be replaced for TDX VMs with TDCALL execution followed by enabling of interrupts. Changes introduced by the series include: - Move *halt() variants outside CONFIG_PARAVIRT_XXL and under CONFIG_PARAVIRT [1]. - Route "sti; hlt" sequences via tdx_safe_halt() for reliability. - Route "hlt" sequences via tdx_halt() to avoid unnecessary #VEs. - Add explicit dependency on CONFIG_PARAVIRT for TDX VMs. - Warn and fail emulation if HLT #VE emulation executes with interrupts enabled. - Clean up TDX specific idle routine override. Changes since v4: 1) Addressed Kirill's comments. v4: https://lore.kernel.org/lkml/20250212000747.3403836-1-vannapurve@google.com/ Changes since v3: 1) Addressed comments from Sean. 2) Included [1] in the series to fix the scenarios where CONFIG_PARAVIRT_XXL could be disabled. v3: https://lore.kernel.org/all/20250206222714.1079059-1-vannapurve@google.com/ [1] https://lore.kernel.org/lkml/20210517235008.257241-1-sathyanarayanan.kuppuswamy@linux.intel.com/ Kirill A. Shutemov (1): x86/paravirt: Move halt paravirt calls under CONFIG_PARAVIRT Vishal Annapurve (3): x86/tdx: Route safe halt execution via tdx_safe_halt() x86/tdx: Emit warning if IRQs are enabled during HLT #VE handling x86/tdx: Remove TDX specific idle routine arch/x86/Kconfig | 1 + arch/x86/coco/tdx/tdx.c | 30 +++++++++++++++++++- arch/x86/include/asm/irqflags.h | 40 +++++++++++++++------------ arch/x86/include/asm/paravirt.h | 20 +++++++------- arch/x86/include/asm/paravirt_types.h | 3 +- arch/x86/include/asm/tdx.h | 2 -- arch/x86/kernel/paravirt.c | 14 ++++++---- arch/x86/kernel/process.c | 3 -- 8 files changed, 71 insertions(+), 42 deletions(-) -- 2.48.1.601.g30ceb7b040-goog