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Mon, 29 Jan 2024 10:06:07 -0800 (PST) Date: Mon, 29 Jan 2024 19:05:19 +0100 In-Reply-To: <20240129180502.4069817-21-ardb+git@google.com> Precedence: bulk X-Mailing-List: linux-arch@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240129180502.4069817-21-ardb+git@google.com> X-Developer-Key: i=ardb@kernel.org; a=openpgp; fpr=F43D03328115A198C90016883D200E9CA6329909 X-Developer-Signature: v=1; a=openpgp-sha256; l=1898; i=ardb@kernel.org; h=from:subject; bh=BAMQXD8G5KJ2RAZEnRCY7V9ynmVKgA6YQxKkMkZhfsc=; b=owGbwMvMwCFmkMcZplerG8N4Wi2JIXX7iwd2nB82KC89l5dabni8zdb++Mqo/SUlzOIzelh7A tI2J/Z2lLIwiHEwyIopsgjM/vtu5+mJUrXOs2Rh5rAygQxh4OIUgImckGb4Z9S36tFe1cvVWzbu ayl98UOoXKWc18nAMa1us+c8oyMr0xn++2XGVlQoGddc37R5goyOv+bk+2UVzxwrL7hu8HNk3C/ PAwA= X-Mailer: git-send-email 2.43.0.429.g432eaa2c6b-goog Message-ID: <20240129180502.4069817-37-ardb+git@google.com> Subject: [PATCH v3 16/19] x86/sev: Avoid WARN() in early code From: Ard Biesheuvel To: linux-kernel@vger.kernel.org Cc: Ard Biesheuvel , Kevin Loughlin , Tom Lendacky , Dionna Glaze , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , Andy Lutomirski , Arnd Bergmann , Nathan Chancellor , Nick Desaulniers , Justin Stitt , Kees Cook , Brian Gerst , linux-arch@vger.kernel.org, llvm@lists.linux.dev Content-Type: text/plain; charset="UTF-8" From: Ard Biesheuvel Drop uses of WARN() from code that is reachable from the early primary boot path which executes via the initial 1:1 mapping before the kernel page tables are populated. This is unsafe and mostly pointless, given that printk() does not actually work yet at this point. Signed-off-by: Ard Biesheuvel --- arch/x86/kernel/sev.c | 13 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-) diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c index 62981b463b76..94bf054bbde3 100644 --- a/arch/x86/kernel/sev.c +++ b/arch/x86/kernel/sev.c @@ -698,7 +698,7 @@ static void __pitext early_set_pages_state(unsigned long vaddr, unsigned long pa if (op == SNP_PAGE_STATE_SHARED) { /* Page validation must be rescinded before changing to shared */ ret = pvalidate(vaddr, RMP_PG_SIZE_4K, false); - if (WARN(ret, "Failed to validate address 0x%lx ret %d", paddr, ret)) + if (ret) goto e_term; } @@ -711,21 +711,16 @@ static void __pitext early_set_pages_state(unsigned long vaddr, unsigned long pa val = sev_es_rd_ghcb_msr(); - if (WARN(GHCB_RESP_CODE(val) != GHCB_MSR_PSC_RESP, - "Wrong PSC response code: 0x%x\n", - (unsigned int)GHCB_RESP_CODE(val))) + if (GHCB_RESP_CODE(val) != GHCB_MSR_PSC_RESP) goto e_term; - if (WARN(GHCB_MSR_PSC_RESP_VAL(val), - "Failed to change page state to '%s' paddr 0x%lx error 0x%llx\n", - op == SNP_PAGE_STATE_PRIVATE ? "private" : "shared", - paddr, GHCB_MSR_PSC_RESP_VAL(val))) + if (GHCB_MSR_PSC_RESP_VAL(val)) goto e_term; if (op == SNP_PAGE_STATE_PRIVATE) { /* Page validation must be performed after changing to private */ ret = pvalidate(vaddr, RMP_PG_SIZE_4K, true); - if (WARN(ret, "Failed to validate address 0x%lx ret %d", paddr, ret)) + if (ret) goto e_term; } -- 2.43.0.429.g432eaa2c6b-goog