From: Tom Lendacky <thomas.lendacky@amd.com>
To: <linux-kernel@vger.kernel.org>, <x86@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
"H. Peter Anvin" <hpa@zytor.com>,
Andy Lutomirski <luto@kernel.org>,
"Peter Zijlstra" <peterz@infradead.org>,
Dan Williams <dan.j.williams@intel.com>,
Michael Roth <michael.roth@amd.com>,
Ashish Kalra <ashish.kalra@amd.com>
Subject: [PATCH 06/11] x86/sev: Use the SVSM to create a vCPU when not in VMPL0
Date: Fri, 26 Jan 2024 16:15:59 -0600 [thread overview]
Message-ID: <bdef30d612044652aafaa82a0abbd81d975fb484.1706307364.git.thomas.lendacky@amd.com> (raw)
In-Reply-To: <cover.1706307364.git.thomas.lendacky@amd.com>
Using the RMPADJUST instruction, the VSMA attribute can only be changed
at VMPL0. An SVSM will be present when running at VMPL1 or a lower
privilege level.
When an SVSM is present, use the SVSM_CORE_CREATE_VCPU call or the
SVSM_CORE_DESTROY_VCPU call to perform VMSA attribute changes. Use the
VMPL level supplied by the SVSM within the VMSA and when starting the
AP.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
---
arch/x86/include/asm/sev.h | 2 ++
arch/x86/kernel/sev.c | 60 +++++++++++++++++++++++++++++++++-----
2 files changed, 54 insertions(+), 8 deletions(-)
diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h
index dbd7fd041689..372bc6183b29 100644
--- a/arch/x86/include/asm/sev.h
+++ b/arch/x86/include/asm/sev.h
@@ -214,6 +214,8 @@ struct svsm_call {
#define SVSM_CORE_CALL(x) ((0ULL << 32) | (x))
#define SVSM_CORE_REMAP_CA 0
#define SVSM_CORE_PVALIDATE 1
+#define SVSM_CORE_CREATE_VCPU 2
+#define SVSM_CORE_DELETE_VCPU 3
#ifdef CONFIG_AMD_MEM_ENCRYPT
extern void __sev_es_ist_enter(struct pt_regs *regs);
diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c
index 2fd21090ef6b..ddb9141f0959 100644
--- a/arch/x86/kernel/sev.c
+++ b/arch/x86/kernel/sev.c
@@ -995,7 +995,7 @@ void snp_accept_memory(phys_addr_t start, phys_addr_t end)
set_pages_state(vaddr, npages, SNP_PAGE_STATE_PRIVATE);
}
-static int snp_set_vmsa(void *va, bool vmsa)
+static int base_snp_set_vmsa(void *va, bool vmsa)
{
u64 attrs;
@@ -1013,6 +1013,40 @@ static int snp_set_vmsa(void *va, bool vmsa)
return rmpadjust((unsigned long)va, RMP_PG_SIZE_4K, attrs);
}
+static int svsm_snp_set_vmsa(void *va, void *caa, int apic_id, bool vmsa)
+{
+ struct svsm_call call = {};
+ unsigned long flags;
+ int ret;
+
+ local_irq_save(flags);
+
+ call.caa = this_cpu_read(svsm_caa);
+ call.rcx = __pa(va);
+
+ if (vmsa) {
+ /* Protocol 0, Call ID 2 */
+ call.rax = SVSM_CORE_CALL(SVSM_CORE_CREATE_VCPU);
+ call.rdx = __pa(caa);
+ call.r8 = apic_id;
+ } else {
+ /* Protocol 0, Call ID 3 */
+ call.rax = SVSM_CORE_CALL(SVSM_CORE_DELETE_VCPU);
+ }
+
+ ret = svsm_protocol(&call);
+
+ local_irq_restore(flags);
+
+ return ret;
+}
+
+static int snp_set_vmsa(void *va, void *caa, int apic_id, bool vmsa)
+{
+ return vmpl ? svsm_snp_set_vmsa(va, caa, apic_id, vmsa)
+ : base_snp_set_vmsa(va, vmsa);
+}
+
#define __ATTR_BASE (SVM_SELECTOR_P_MASK | SVM_SELECTOR_S_MASK)
#define INIT_CS_ATTRIBS (__ATTR_BASE | SVM_SELECTOR_READ_MASK | SVM_SELECTOR_CODE_MASK)
#define INIT_DS_ATTRIBS (__ATTR_BASE | SVM_SELECTOR_WRITE_MASK)
@@ -1044,11 +1078,11 @@ static void *snp_alloc_vmsa_page(void)
return page_address(p + 1);
}
-static void snp_cleanup_vmsa(struct sev_es_save_area *vmsa)
+static void snp_cleanup_vmsa(struct sev_es_save_area *vmsa, int apic_id)
{
int err;
- err = snp_set_vmsa(vmsa, false);
+ err = snp_set_vmsa(vmsa, NULL, apic_id, false);
if (err)
pr_err("clear VMSA page failed (%u), leaking page\n", err);
else
@@ -1059,6 +1093,7 @@ static int wakeup_cpu_via_vmgexit(u32 apic_id, unsigned long start_ip)
{
struct sev_es_save_area *cur_vmsa, *vmsa;
struct ghcb_state state;
+ struct svsm_ca *caa;
unsigned long flags;
struct ghcb *ghcb;
u8 sipi_vector;
@@ -1105,6 +1140,12 @@ static int wakeup_cpu_via_vmgexit(u32 apic_id, unsigned long start_ip)
if (!vmsa)
return -ENOMEM;
+ /*
+ * If an SVSM is present, then the SVSM CAA per-CPU variable will
+ * have a value, otherwise it will be NULL.
+ */
+ caa = per_cpu(svsm_caa, cpu);
+
/* CR4 should maintain the MCE value */
cr4 = native_read_cr4() & X86_CR4_MCE;
@@ -1152,11 +1193,11 @@ static int wakeup_cpu_via_vmgexit(u32 apic_id, unsigned long start_ip)
* VMPL level
* SEV_FEATURES (matches the SEV STATUS MSR right shifted 2 bits)
*/
- vmsa->vmpl = 0;
+ vmsa->vmpl = vmpl;
vmsa->sev_features = sev_status >> 2;
/* Switch the page over to a VMSA page now that it is initialized */
- ret = snp_set_vmsa(vmsa, true);
+ ret = snp_set_vmsa(vmsa, caa, apic_id, true);
if (ret) {
pr_err("set VMSA page failed (%u)\n", ret);
free_page((unsigned long)vmsa);
@@ -1172,7 +1213,10 @@ static int wakeup_cpu_via_vmgexit(u32 apic_id, unsigned long start_ip)
vc_ghcb_invalidate(ghcb);
ghcb_set_rax(ghcb, vmsa->sev_features);
ghcb_set_sw_exit_code(ghcb, SVM_VMGEXIT_AP_CREATION);
- ghcb_set_sw_exit_info_1(ghcb, ((u64)apic_id << 32) | SVM_VMGEXIT_AP_CREATE);
+ ghcb_set_sw_exit_info_1(ghcb,
+ ((u64)apic_id << 32) |
+ ((u64)vmpl << 16) |
+ SVM_VMGEXIT_AP_CREATE);
ghcb_set_sw_exit_info_2(ghcb, __pa(vmsa));
sev_es_wr_ghcb_msr(__pa(ghcb));
@@ -1190,13 +1234,13 @@ static int wakeup_cpu_via_vmgexit(u32 apic_id, unsigned long start_ip)
/* Perform cleanup if there was an error */
if (ret) {
- snp_cleanup_vmsa(vmsa);
+ snp_cleanup_vmsa(vmsa, apic_id);
vmsa = NULL;
}
/* Free up any previous VMSA page */
if (cur_vmsa)
- snp_cleanup_vmsa(cur_vmsa);
+ snp_cleanup_vmsa(cur_vmsa, apic_id);
/* Record the current VMSA page */
per_cpu(sev_vmsa, cpu) = vmsa;
--
2.42.0
next prev parent reply other threads:[~2024-01-26 22:16 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-26 22:15 [PATCH 00/11] Provide SEV-SNP support for running under an SVSM Tom Lendacky
2024-01-26 22:15 ` [PATCH 01/11] x86/sev: Rename snp_init() in the boot/compressed/sev.c file Tom Lendacky
2024-01-27 0:05 ` Dionna Amalie Glaze
2024-01-27 14:38 ` Tom Lendacky
2024-01-26 22:15 ` [PATCH 02/11] x86/sev: Make the VMPL0 checking function more generic Tom Lendacky
2024-01-26 22:15 ` [PATCH 03/11] x86/sev: Check for the presence of an SVSM in the SNP Secrets page Tom Lendacky
2024-01-26 22:15 ` [PATCH 04/11] x86/sev: Use kernel provided SVSM Calling Areas Tom Lendacky
2024-01-27 0:45 ` Dionna Amalie Glaze
2024-01-27 14:43 ` Tom Lendacky
2024-01-26 22:15 ` [PATCH 05/11] x86/sev: Perform PVALIDATE using the SVSM when not at VMPL0 Tom Lendacky
2024-01-27 0:59 ` Dionna Amalie Glaze
2024-01-27 15:18 ` Tom Lendacky
2024-01-26 22:15 ` Tom Lendacky [this message]
2024-01-26 22:16 ` [PATCH 07/11] x86/sev: Provide SVSM discovery support Tom Lendacky
2024-01-29 10:41 ` Jeremi Piotrowski
2024-01-29 15:18 ` Tom Lendacky
2024-01-26 22:16 ` [PATCH 08/11] x86/sev: Provide guest VMPL level to userspace Tom Lendacky
2024-01-27 1:06 ` Dionna Amalie Glaze
2024-01-27 15:43 ` Tom Lendacky
2024-01-26 22:16 ` [PATCH 09/11] virt: sev-guest: Choose the VMPCK key based on executing VMPL Tom Lendacky
2024-01-26 22:16 ` [PATCH 10/11] x86/sev: Extend the config-fs attestation support for an SVSM Tom Lendacky
2024-01-27 1:27 ` Dionna Amalie Glaze
2024-01-29 15:02 ` Tom Lendacky
2024-01-29 20:04 ` Dionna Amalie Glaze
2024-02-01 21:14 ` Tom Lendacky
2024-02-02 7:10 ` Dan Williams
2024-02-05 23:29 ` Kuppuswamy, Sathyanarayanan
2024-02-06 18:53 ` Tom Lendacky
2024-02-06 18:48 ` Tom Lendacky
2024-02-13 2:34 ` Dan Williams
2024-02-16 19:07 ` Tom Lendacky
2024-02-16 20:46 ` Dan Williams
2024-02-23 20:41 ` Tom Lendacky
2024-02-24 0:02 ` Dan Williams
2024-02-26 14:42 ` Tom Lendacky
2024-01-26 22:16 ` [PATCH 11/11] x86/sev: Allow non-VMPL0 execution when an SVSM is present Tom Lendacky
2024-02-12 10:40 ` [PATCH 00/11] Provide SEV-SNP support for running under an SVSM Reshetova, Elena
2024-02-16 19:46 ` Tom Lendacky
2024-02-19 16:57 ` Shutemov, Kirill
2024-02-19 17:54 ` Reshetova, Elena
2024-02-23 20:23 ` Tom Lendacky
2024-02-27 14:56 ` Reshetova, Elena
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