KVM: Don't pre-reserve xarray entries when storing empty/NULL attributesgrafted

Skip the xarray reservation loop when clearing all memory attributes, as
storing NULL only erases the entry and never needs to allocate, so no
reservation (and no cleanup of a failed one) is required in that case.

Suggested-by: Sean Christopherson <seanjc@google.com>
Cc: David Ballesteros <davimaba.v@proton.me>
Signed-off-by: Zeng Chi <zengchi@kylinos.cn>
Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com
[sean: split to separate patch]
Signed-off-by: Sean Christopherson <seanjc@google.com>

1 files changed, 399 insertions, 0 deletions

diff --git a/drivers/crypto/ccp/sev-dev-tsm.c b/drivers/crypto/ccp/sev-dev-tsm.c
new file mode 100644
index 000000000..46f2539d2
--- /dev/null
+++ b/drivers/crypto/ccp/sev-dev-tsm.c
@@ -0,0 +1,399 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+// Interface to CCP/SEV-TIO for generic PCIe TDISP module
+
+#include <linux/pci.h>
+#include <linux/device.h>
+#include <linux/tsm.h>
+#include <linux/iommu.h>
+#include <linux/pci-doe.h>
+#include <linux/bitfield.h>
+#include <linux/module.h>
+
+#include <asm/sev-common.h>
+#include <asm/sev.h>
+
+#include "psp-dev.h"
+#include "sev-dev.h"
+#include "sev-dev-tio.h"
+
+MODULE_IMPORT_NS("PCI_IDE");
+
+#define dev_to_sp(dev)		((struct sp_device *)dev_get_drvdata(dev))
+#define dev_to_psp(dev)		((struct psp_device *)(dev_to_sp(dev)->psp_data))
+#define dev_to_sev(dev)		((struct sev_device *)(dev_to_psp(dev)->sev_data))
+#define tsm_dev_to_sev(tsmdev)	dev_to_sev((tsmdev)->dev.parent)
+
+#define pdev_to_tio_dsm(pdev)	(container_of((pdev)->tsm, struct tio_dsm, tsm.base_tsm))
+
+static int sev_tio_spdm_cmd(struct tio_dsm *dsm, int ret)
+{
+	struct tsm_dsm_tio *dev_data = &dsm->data;
+	struct tsm_spdm *spdm = &dev_data->spdm;
+
+	/* Check the main command handler response before entering the loop */
+	if (ret == 0 && dev_data->psp_ret != SEV_RET_SUCCESS)
+		return -EINVAL;
+
+	if (ret <= 0)
+		return ret;
+
+	/* ret > 0 means "SPDM requested" */
+	while (ret == PCI_DOE_FEATURE_CMA || ret == PCI_DOE_FEATURE_SSESSION) {
+		ret = pci_doe(dsm->tsm.doe_mb, PCI_VENDOR_ID_PCI_SIG, ret,
+			      spdm->req, spdm->req_len, spdm->rsp, spdm->rsp_len);
+		if (ret < 0)
+			break;
+
+		WARN_ON_ONCE(ret == 0); /* The response should never be empty */
+		spdm->rsp_len = ret;
+		ret = sev_tio_continue(dev_data);
+	}
+
+	return ret;
+}
+
+static int stream_enable(struct pci_ide *ide)
+{
+	struct pci_dev *rp = pcie_find_root_port(ide->pdev);
+	int ret;
+
+	ret = pci_ide_stream_enable(ide->pdev, ide);
+	if (ret && ret != -ENXIO)
+		return ret;
+
+	ret = pci_ide_stream_enable(rp, ide);
+	if (ret && ret != -ENXIO)
+		pci_ide_stream_disable(ide->pdev, ide);
+
+	return ret;
+}
+
+static int streams_enable(struct pci_ide **ide)
+{
+	int ret = 0;
+
+	for (int i = 0; i < TIO_IDE_MAX_TC; ++i) {
+		if (ide[i]) {
+			ret = stream_enable(ide[i]);
+			if (ret)
+				break;
+		}
+	}
+
+	return ret;
+}
+
+static void stream_disable(struct pci_ide *ide)
+{
+	pci_ide_stream_disable(ide->pdev, ide);
+	pci_ide_stream_disable(pcie_find_root_port(ide->pdev), ide);
+}
+
+static void streams_disable(struct pci_ide **ide)
+{
+	for (int i = 0; i < TIO_IDE_MAX_TC; ++i)
+		if (ide[i])
+			stream_disable(ide[i]);
+}
+
+static void stream_setup(struct pci_ide *ide)
+{
+	struct pci_dev *rp = pcie_find_root_port(ide->pdev);
+
+	ide->partner[PCI_IDE_EP].rid_start = 0;
+	ide->partner[PCI_IDE_EP].rid_end = 0xffff;
+	ide->partner[PCI_IDE_RP].rid_start = 0;
+	ide->partner[PCI_IDE_RP].rid_end = 0xffff;
+
+	ide->pdev->ide_cfg = 0;
+	ide->pdev->ide_tee_limit = 1;
+	rp->ide_cfg = 1;
+	rp->ide_tee_limit = 0;
+
+	pci_warn(ide->pdev, "Forcing CFG/TEE for %s", pci_name(rp));
+	pci_ide_stream_setup(ide->pdev, ide);
+	pci_ide_stream_setup(rp, ide);
+}
+
+static u8 streams_setup(struct pci_ide **ide, u8 *ids)
+{
+	bool def = false;
+	u8 tc_mask = 0;
+	int i;
+
+	for (i = 0; i < TIO_IDE_MAX_TC; ++i) {
+		if (!ide[i]) {
+			ids[i] = 0xFF;
+			continue;
+		}
+
+		tc_mask |= BIT(i);
+		ids[i] = ide[i]->stream_id;
+
+		if (!def) {
+			struct pci_ide_partner *settings;
+
+			settings = pci_ide_to_settings(ide[i]->pdev, ide[i]);
+			settings->default_stream = 1;
+			def = true;
+		}
+
+		stream_setup(ide[i]);
+	}
+
+	return tc_mask;
+}
+
+static int streams_register(struct pci_ide **ide)
+{
+	int ret = 0, i;
+
+	for (i = 0; i < TIO_IDE_MAX_TC; ++i) {
+		if (ide[i]) {
+			ret = pci_ide_stream_register(ide[i]);
+			if (ret)
+				break;
+		}
+	}
+
+	return ret;
+}
+
+static void streams_unregister(struct pci_ide **ide)
+{
+	for (int i = 0; i < TIO_IDE_MAX_TC; ++i)
+		if (ide[i])
+			pci_ide_stream_unregister(ide[i]);
+}
+
+static void stream_teardown(struct pci_ide *ide)
+{
+	pci_ide_stream_teardown(ide->pdev, ide);
+	pci_ide_stream_teardown(pcie_find_root_port(ide->pdev), ide);
+}
+
+static void streams_teardown(struct pci_ide **ide)
+{
+	for (int i = 0; i < TIO_IDE_MAX_TC; ++i) {
+		if (ide[i]) {
+			stream_teardown(ide[i]);
+			pci_ide_stream_free(ide[i]);
+			ide[i] = NULL;
+		}
+	}
+}
+
+static int stream_alloc(struct pci_dev *pdev, struct pci_ide **ide,
+			unsigned int tc)
+{
+	struct pci_ide *ide1;
+
+	if (ide[tc]) {
+		pci_err(pdev, "Stream for class=%d already registered", tc);
+		return -EBUSY;
+	}
+
+	ide1 = pci_ide_stream_alloc(pdev);
+	if (!ide1)
+		return -EFAULT;
+
+	ide1->stream_id = ide1->host_bridge_stream;
+
+	ide[tc] = ide1;
+
+	return 0;
+}
+
+static struct pci_tsm *tio_pf0_probe(struct pci_dev *pdev, struct sev_device *sev)
+{
+	struct tio_dsm *dsm __free(kfree) = kzalloc_obj(*dsm);
+	int rc;
+
+	if (!dsm)
+		return NULL;
+
+	rc = pci_tsm_pf0_constructor(pdev, &dsm->tsm, sev->tsmdev);
+	if (rc)
+		return NULL;
+
+	pci_dbg(pdev, "TSM enabled\n");
+	dsm->sev = sev;
+	return &no_free_ptr(dsm)->tsm.base_tsm;
+}
+
+static struct pci_tsm *dsm_probe(struct tsm_dev *tsmdev, struct pci_dev *pdev)
+{
+	struct sev_device *sev = tsm_dev_to_sev(tsmdev);
+
+	if (is_pci_tsm_pf0(pdev))
+		return tio_pf0_probe(pdev, sev);
+	return NULL;
+}
+
+static void dsm_remove(struct pci_tsm *tsm)
+{
+	struct pci_dev *pdev = tsm->pdev;
+
+	pci_dbg(pdev, "TSM disabled\n");
+
+	if (is_pci_tsm_pf0(pdev)) {
+		struct tio_dsm *dsm = container_of(tsm, struct tio_dsm, tsm.base_tsm);
+
+		pci_tsm_pf0_destructor(&dsm->tsm);
+		kfree(dsm);
+	}
+}
+
+static int dsm_create(struct tio_dsm *dsm)
+{
+	struct pci_dev *pdev = dsm->tsm.base_tsm.pdev;
+	struct pci_dev *rootport;
+	u8 segment_id;
+	u16 device_id;
+	u16 root_port_id;
+	u32 lnkcap = 0;
+
+	if (!pdev->bus)
+		return -ENODEV;
+
+	segment_id = pci_domain_nr(pdev->bus);
+	rootport = pcie_find_root_port(pdev);
+	device_id = pci_dev_id(pdev);
+
+	if (pci_read_config_dword(rootport, pci_pcie_cap(rootport) + PCI_EXP_LNKCAP,
+				  &lnkcap))
+		return -ENODEV;
+
+	root_port_id = FIELD_GET(PCI_EXP_LNKCAP_PN, lnkcap);
+
+	return sev_tio_dev_create(&dsm->data, device_id, root_port_id, segment_id);
+}
+
+static int dsm_connect(struct pci_dev *pdev)
+{
+	struct tio_dsm *dsm = pdev_to_tio_dsm(pdev);
+	struct tsm_dsm_tio *dev_data = &dsm->data;
+	u8 ids[TIO_IDE_MAX_TC];
+	u8 tc_mask;
+	int ret;
+
+	if (pci_find_doe_mailbox(pdev, PCI_VENDOR_ID_PCI_SIG,
+				 PCI_DOE_FEATURE_SSESSION) != dsm->tsm.doe_mb) {
+		pci_err(pdev, "CMA DOE MB must support SSESSION\n");
+		return -EFAULT;
+	}
+
+	ret = stream_alloc(pdev, dev_data->ide, 0);
+	if (ret)
+		return ret;
+
+	ret = dsm_create(dsm);
+	if (ret)
+		goto ide_free_exit;
+
+	tc_mask = streams_setup(dev_data->ide, ids);
+
+	ret = sev_tio_dev_connect(dev_data, tc_mask, ids, dev_data->cert_slot);
+	ret = sev_tio_spdm_cmd(dsm, ret);
+	if (ret)
+		goto free_exit;
+
+	streams_enable(dev_data->ide);
+
+	ret = streams_register(dev_data->ide);
+	if (ret)
+		goto free_exit;
+
+	return 0;
+
+free_exit:
+	sev_tio_dev_reclaim(dev_data);
+
+	streams_disable(dev_data->ide);
+ide_free_exit:
+
+	streams_teardown(dev_data->ide);
+
+	return ret;
+}
+
+static void dsm_disconnect(struct pci_dev *pdev)
+{
+	bool force = SYSTEM_HALT <= system_state && system_state <= SYSTEM_RESTART;
+	struct tio_dsm *dsm = pdev_to_tio_dsm(pdev);
+	struct tsm_dsm_tio *dev_data = &dsm->data;
+	int ret;
+
+	ret = sev_tio_dev_disconnect(dev_data, force);
+	ret = sev_tio_spdm_cmd(dsm, ret);
+	if (ret && !force) {
+		ret = sev_tio_dev_disconnect(dev_data, true);
+		sev_tio_spdm_cmd(dsm, ret);
+	}
+
+	sev_tio_dev_reclaim(dev_data);
+
+	streams_disable(dev_data->ide);
+	streams_unregister(dev_data->ide);
+	streams_teardown(dev_data->ide);
+}
+
+static struct pci_tsm_ops sev_tsm_ops = {
+	.probe = dsm_probe,
+	.remove = dsm_remove,
+	.connect = dsm_connect,
+	.disconnect = dsm_disconnect,
+};
+
+void sev_tsm_init_locked(struct sev_device *sev, void *tio_status_page)
+{
+	struct sev_tio_status *t = kzalloc_obj(*t);
+	struct tsm_dev *tsmdev;
+	int ret;
+
+	WARN_ON(sev->tio_status);
+
+	if (!t)
+		return;
+
+	ret = sev_tio_init_locked(tio_status_page);
+	if (ret) {
+		pr_warn("SEV-TIO STATUS failed with %d\n", ret);
+		goto error_exit;
+	}
+
+	tsmdev = tsm_register(sev->dev, &sev_tsm_ops);
+	if (IS_ERR(tsmdev))
+		goto error_exit;
+
+	memcpy(t, tio_status_page, sizeof(*t));
+
+	pr_notice("SEV-TIO status: EN=%d INIT_DONE=%d rq=%d..%d rs=%d..%d "
+		  "scr=%d..%d out=%d..%d dev=%d tdi=%d algos=%x\n",
+		  t->tio_en, t->tio_init_done,
+		  t->spdm_req_size_min, t->spdm_req_size_max,
+		  t->spdm_rsp_size_min, t->spdm_rsp_size_max,
+		  t->spdm_scratch_size_min, t->spdm_scratch_size_max,
+		  t->spdm_out_size_min, t->spdm_out_size_max,
+		  t->devctx_size, t->tdictx_size,
+		  t->tio_crypto_alg);
+
+	sev->tsmdev = tsmdev;
+	sev->tio_status = t;
+
+	return;
+
+error_exit:
+	pr_err("Failed to enable SEV-TIO: ret=%d en=%d initdone=%d SEV=%d\n",
+	       ret, t->tio_en, t->tio_init_done, boot_cpu_has(X86_FEATURE_SEV));
+	kfree(t);
+}
+
+void sev_tsm_uninit(struct sev_device *sev)
+{
+	if (sev->tsmdev)
+		tsm_unregister(sev->tsmdev);
+
+	sev->tsmdev = NULL;
+}