Message-ID: <20241112232253.3379178-8-dionnaglaze@google.com>
Date: Tue, 12 Nov 2024 23:22:46 +0000
From: Dionna Glaze <dionnaglaze@...gle.com>
To: linux-kernel@...r.kernel.org, x86@...nel.org, 
	Sean Christopherson <seanjc@...gle.com>, Paolo Bonzini <pbonzini@...hat.com>, 
	Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>, 
	Dave Hansen <dave.hansen@...ux.intel.com>, "H. Peter Anvin" <hpa@...or.com>
Cc: linux-coco@...ts.linux.dev, Dionna Glaze <dionnaglaze@...gle.com>, 
	Ashish Kalra <ashish.kalra@....com>, Tom Lendacky <thomas.lendacky@....com>, 
	John Allen <john.allen@....com>, Herbert Xu <herbert@...dor.apana.org.au>, 
	"David S. Miller" <davem@...emloft.net>, Michael Roth <michael.roth@....com>, 
	Luis Chamberlain <mcgrof@...nel.org>, Russ Weight <russ.weight@...ux.dev>, 
	Danilo Krummrich <dakr@...hat.com>, Greg Kroah-Hartman <gregkh@...uxfoundation.org>, 
	"Rafael J. Wysocki" <rafael@...nel.org>, Tianfei zhang <tianfei.zhang@...el.com>, 
	Alexey Kardashevskiy <aik@....com>, kvm@...r.kernel.org
Subject: [PATCH v6 7/8] KVM: SVM: Use new ccp GCTX API

Guest context pages should be near 1-to-1 with allocated ASIDs. With the
GCTX API, the ccp driver is better able to associate guest context pages
with the ASID that is/will be bound to it.

This is important to the firmware hotloading implementation to not
corrupt any running VM's guest context page before userspace commits a
new firmware.

CC: Sean Christopherson <seanjc@...gle.com>
CC: Paolo Bonzini <pbonzini@...hat.com>
CC: Thomas Gleixner <tglx@...utronix.de>
CC: Ingo Molnar <mingo@...hat.com>
CC: Borislav Petkov <bp@...en8.de>
CC: Dave Hansen <dave.hansen@...ux.intel.com>
CC: Ashish Kalra <ashish.kalra@....com>
CC: Tom Lendacky <thomas.lendacky@....com>
CC: John Allen <john.allen@....com>
CC: Herbert Xu <herbert@...dor.apana.org.au>
CC: "David S. Miller" <davem@...emloft.net>
CC: Michael Roth <michael.roth@....com>
CC: Luis Chamberlain <mcgrof@...nel.org>
CC: Russ Weight <russ.weight@...ux.dev>
CC: Danilo Krummrich <dakr@...hat.com>
CC: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
CC: "Rafael J. Wysocki" <rafael@...nel.org>
CC: Tianfei zhang <tianfei.zhang@...el.com>
CC: Alexey Kardashevskiy <aik@....com>

Signed-off-by: Dionna Glaze <dionnaglaze@...gle.com>
---
 arch/x86/kvm/svm/sev.c | 60 ++++++++----------------------------------
 1 file changed, 11 insertions(+), 49 deletions(-)

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index d0e0152aefb32..5e6d1f1c14dfd 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -2156,51 +2156,12 @@ int sev_dev_get_attr(u32 group, u64 attr, u64 *val)
 	}
 }
 
-/*
- * The guest context contains all the information, keys and metadata
- * associated with the guest that the firmware tracks to implement SEV
- * and SNP features. The firmware stores the guest context in hypervisor
- * provide page via the SNP_GCTX_CREATE command.
- */
-static void *snp_context_create(struct kvm *kvm, struct kvm_sev_cmd *argp)
-{
-	struct sev_data_snp_addr data = {};
-	void *context;
-	int rc;
-
-	/* Allocate memory for context page */
-	context = snp_alloc_firmware_page(GFP_KERNEL_ACCOUNT);
-	if (!context)
-		return ERR_PTR(-ENOMEM);
-
-	data.address = __psp_pa(context);
-	rc = __sev_issue_cmd(argp->sev_fd, SEV_CMD_SNP_GCTX_CREATE, &data, &argp->error);
-	if (rc) {
-		pr_warn("Failed to create SEV-SNP context, rc %d fw_error %d",
-			rc, argp->error);
-		snp_free_firmware_page(context);
-		return ERR_PTR(rc);
-	}
-
-	return context;
-}
-
-static int snp_bind_asid(struct kvm *kvm, int *error)
-{
-	struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
-	struct sev_data_snp_activate data = {0};
-
-	data.gctx_paddr = __psp_pa(sev->snp_context);
-	data.asid = sev_get_asid(kvm);
-	return sev_issue_cmd(kvm, SEV_CMD_SNP_ACTIVATE, &data, error);
-}
-
 static int snp_launch_start(struct kvm *kvm, struct kvm_sev_cmd *argp)
 {
 	struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
 	struct sev_data_snp_launch_start start = {0};
 	struct kvm_sev_snp_launch_start params;
-	int rc;
+	int rc, asid;
 
 	if (!sev_snp_guest(kvm))
 		return -ENOTTY;
@@ -2226,7 +2187,8 @@ static int snp_launch_start(struct kvm *kvm, struct kvm_sev_cmd *argp)
 	if (params.policy & SNP_POLICY_MASK_SINGLE_SOCKET)
 		return -EINVAL;
 
-	sev->snp_context = snp_context_create(kvm, argp);
+	asid = sev_get_asid(kvm);
+	sev->snp_context = sev_snp_create_context(argp->sev_fd, asid, &argp->error);
 	if (IS_ERR(sev->snp_context))
 		return PTR_ERR(sev->snp_context);
 
@@ -2241,7 +2203,7 @@ static int snp_launch_start(struct kvm *kvm, struct kvm_sev_cmd *argp)
 	}
 
 	sev->fd = argp->sev_fd;
-	rc = snp_bind_asid(kvm, &argp->error);
+	rc = sev_snp_activate_asid(sev->fd, asid, &argp->error);
 	if (rc) {
 		pr_debug("%s: Failed to bind ASID to SEV-SNP context, rc %d\n",
 			 __func__, rc);
@@ -2865,23 +2827,23 @@ int sev_vm_copy_enc_context_from(struct kvm *kvm, unsigned int source_fd)
 static int snp_decommission_context(struct kvm *kvm)
 {
 	struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
-	struct sev_data_snp_addr data = {};
-	int ret;
+	int ret, error;
 
 	/* If context is not created then do nothing */
 	if (!sev->snp_context)
 		return 0;
 
-	/* Do the decommision, which will unbind the ASID from the SNP context */
-	data.address = __sme_pa(sev->snp_context);
+	/*
+	 * Do the decommision, which will unbind the ASID from the SNP context
+	 * and free the context page.
+	 */
 	down_write(&sev_deactivate_lock);
-	ret = sev_do_cmd(SEV_CMD_SNP_DECOMMISSION, &data, NULL);
+	ret = sev_snp_guest_decommission(sev->fd, sev->asid, &error);
 	up_write(&sev_deactivate_lock);
 
-	if (WARN_ONCE(ret, "Failed to release guest context, ret %d", ret))
+	if (WARN_ONCE(ret, "Failed to release guest context, ret %d fw err %d", ret, error))
 		return ret;
 
-	snp_free_firmware_page(sev->snp_context);
 	sev->snp_context = NULL;
 
 	return 0;
-- 
2.47.0.277.g8800431eea-goog

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