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b=z4c40GeCEMr/TW1oHB73U4B5WcnJSedcurQAE94MyBo6WFgK42HxcKhqjmp2lpb5ZdWbVi 7277un7GXALgZjCA== Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id 8027B3EA65; Fri, 19 Dec 2025 11:43:38 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id gMqOHGo6RWnWGgAAD6G6ig (envelope-from ); Fri, 19 Dec 2025 11:43:38 +0000 From: =?UTF-8?q?Carlos=20L=C3=B3pez?= To: kvm@vger.kernel.org, seanjc@google.com, pbonzini@redhat.com Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org, =?UTF-8?q?Carlos=20L=C3=B3pez?= Subject: [PATCH 1/6] KVM: SEV: use mutex guard in snp_launch_update() Date: Fri, 19 Dec 2025 12:41:56 +0100 Message-ID: <20251219114238.3797364-2-clopez@suse.de> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251219114238.3797364-1-clopez@suse.de> References: <20251219114238.3797364-1-clopez@suse.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-Spamd-Result: default: False [-4.51 / 50.00]; BAYES_HAM(-3.00)[100.00%]; DWL_DNSWL_LOW(-1.00)[suse.de:dkim]; MID_CONTAINS_FROM(1.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; R_DKIM_ALLOW(-0.20)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; NEURAL_HAM_SHORT(-0.20)[-0.998]; MIME_GOOD(-0.10)[text/plain]; MX_GOOD(-0.01)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; FUZZY_RATELIMITED(0.00)[rspamd.com]; ARC_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; RCVD_TLS_ALL(0.00)[]; DNSWL_BLOCKED(0.00)[2a07:de40:b281:104:10:150:64:97:from]; TO_DN_SOME(0.00)[]; FROM_EQ_ENVFROM(0.00)[]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_SEVEN(0.00)[11]; RCVD_COUNT_TWO(0.00)[2]; TO_MATCH_ENVRCPT_ALL(0.00)[]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.de:email,suse.de:dkim,suse.de:mid,imap1.dmz-prg2.suse.org:helo,imap1.dmz-prg2.suse.org:rdns]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; DKIM_TRACE(0.00)[suse.de:+] X-Rspamd-Action: no action X-Rspamd-Server: rspamd2.dmz-prg2.suse.org X-Spam-Level: X-Rspamd-Queue-Id: 2482C33700 X-Spam-Flag: NO X-Spam-Score: -4.51 Simplify the error paths in snp_launch_update() by using a mutex guard, allowing early return instead of using gotos. Signed-off-by: Carlos L=C3=B3pez Reviewed-by: Pankaj Gupta --- arch/x86/kvm/svm/sev.c | 32 +++++++++++++------------------- 1 file changed, 13 insertions(+), 19 deletions(-) diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index f59c65abe3cf..1b325ae61d15 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -8,6 +8,7 @@ */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt =20 +#include #include #include #include @@ -2367,7 +2368,6 @@ static int snp_launch_update(struct kvm *kvm, struct = kvm_sev_cmd *argp) struct kvm_memory_slot *memslot; long npages, count; void __user *src; - int ret =3D 0; =20 if (!sev_snp_guest(kvm) || !sev->snp_context) return -EINVAL; @@ -2407,13 +2407,11 @@ static int snp_launch_update(struct kvm *kvm, struc= t kvm_sev_cmd *argp) * initial expected state and better guard against unexpected * situations. */ - mutex_lock(&kvm->slots_lock); + guard(mutex)(&kvm->slots_lock); =20 memslot =3D gfn_to_memslot(kvm, params.gfn_start); - if (!kvm_slot_has_gmem(memslot)) { - ret =3D -EINVAL; - goto out; - } + if (!kvm_slot_has_gmem(memslot)) + return -EINVAL; =20 sev_populate_args.sev_fd =3D argp->sev_fd; sev_populate_args.type =3D params.type; @@ -2425,22 +2423,18 @@ static int snp_launch_update(struct kvm *kvm, struc= t kvm_sev_cmd *argp) argp->error =3D sev_populate_args.fw_error; pr_debug("%s: kvm_gmem_populate failed, ret %ld (fw_error %d)\n", __func__, count, argp->error); - ret =3D -EIO; - } else { - params.gfn_start +=3D count; - params.len -=3D count * PAGE_SIZE; - if (params.type !=3D KVM_SEV_SNP_PAGE_TYPE_ZERO) - params.uaddr +=3D count * PAGE_SIZE; - - ret =3D 0; - if (copy_to_user(u64_to_user_ptr(argp->data), ¶ms, sizeof(params))) - ret =3D -EFAULT; + return -EIO; } =20 -out: - mutex_unlock(&kvm->slots_lock); + params.gfn_start +=3D count; + params.len -=3D count * PAGE_SIZE; + if (params.type !=3D KVM_SEV_SNP_PAGE_TYPE_ZERO) + params.uaddr +=3D count * PAGE_SIZE; =20 - return ret; + if (copy_to_user(u64_to_user_ptr(argp->data), ¶ms, sizeof(params))) + return -EFAULT; + + return 0; } =20 static int snp_launch_update_vmsa(struct kvm *kvm, struct kvm_sev_cmd *arg= p) --=20 2.51.0