From: Tom Lendacky <thomas.lendacky@amd.com>
To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org
Cc: Paolo Bonzini <pbonzini@redhat.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
Sean Christopherson <sean.j.christopherson@intel.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Borislav Petkov <bp@alien8.de>, Ingo Molnar <mingo@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
Brijesh Singh <brijesh.singh@amd.com>
Subject: [RFC PATCH 33/35] KVM: SVM: Provide support for SEV-ES vCPU loading
Date: Mon, 14 Sep 2020 15:15:47 -0500 [thread overview]
Message-ID: <3da36e824a62f2874b21dea496d50892611a8bdd.1600114548.git.thomas.lendacky@amd.com> (raw)
In-Reply-To: <cover.1600114548.git.thomas.lendacky@amd.com>
From: Tom Lendacky <thomas.lendacky@amd.com>
An SEV-ES vCPU requires additional VMCB vCPU load/put requirements. SEV-ES
hardware will restore certain registers on VMEXIT, but not save them on
VMRUM (see Table B-3 and Table B-4 of the AMD64 APM Volume 2), so make the
following changes:
General vCPU load changes:
- During vCPU loading, perform a VMSAVE to the per-CPU SVM save area and
save the current value of XCR0 to the per-CPU SVM save area as these
registers will be restored on VMEXIT.
General vCPU put changes:
- Do not attempt to restore registers that SEV-ES hardware has already
restored on VMEXIT.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
---
arch/x86/kvm/svm/sev.c | 48 ++++++++++++++++++++++++++++++++++++++++++
arch/x86/kvm/svm/svm.c | 36 +++++++++++++++++++------------
arch/x86/kvm/svm/svm.h | 22 +++++++++++++------
3 files changed, 87 insertions(+), 19 deletions(-)
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 7ed88f2e8d93..50018436863b 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -17,11 +17,14 @@
#include <linux/trace_events.h>
#include <asm/trapnr.h>
+#include <asm/fpu/internal.h>
#include "x86.h"
#include "svm.h"
#include "trace.h"
+#define __ex(x) __kvm_handle_fault_on_reboot(x)
+
static u8 sev_enc_bit;
static int sev_flush_asids(void);
static DECLARE_RWSEM(sev_deactivate_lock);
@@ -1599,3 +1602,48 @@ void sev_es_create_vcpu(struct vcpu_svm *svm)
GHCB_VERSION_MIN,
sev_enc_bit));
}
+
+void sev_es_vcpu_load(struct vcpu_svm *svm, int cpu)
+{
+ struct svm_cpu_data *sd = per_cpu(svm_data, cpu);
+ struct vmcb_save_area *hostsa;
+ unsigned int i;
+
+ /*
+ * As an SEV-ES guest, hardware will restore the host state on VMEXIT,
+ * of which one step is to perform a VMLOAD. Since hardware does not
+ * perform a VMSAVE on VMRUN, the host savearea must be updated.
+ */
+ asm volatile(__ex("vmsave") : : "a" (__sme_page_pa(sd->save_area)) : "memory");
+
+ /*
+ * Certain MSRs are restored on VMEXIT, only save ones that aren't
+ * saved via the vmsave above.
+ */
+ for (i = 0; i < NR_HOST_SAVE_USER_MSRS; i++) {
+ if (host_save_user_msrs[i].sev_es_restored)
+ continue;
+
+ rdmsrl(host_save_user_msrs[i].index, svm->host_user_msrs[i]);
+ }
+
+ /* XCR0 is restored on VMEXIT, save the current host value */
+ hostsa = (struct vmcb_save_area *)(page_address(sd->save_area) + 0x400);
+ hostsa->xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK);
+}
+
+void sev_es_vcpu_put(struct vcpu_svm *svm)
+{
+ unsigned int i;
+
+ /*
+ * Certain MSRs are restored on VMEXIT and were saved with vmsave in
+ * sev_es_vcpu_load() above. Only restore ones that weren't.
+ */
+ for (i = 0; i < NR_HOST_SAVE_USER_MSRS; i++) {
+ if (host_save_user_msrs[i].sev_es_restored)
+ continue;
+
+ wrmsrl(host_save_user_msrs[i].index, svm->host_user_msrs[i]);
+ }
+}
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index cb9b1d281adb..efefe8ba9759 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -1340,15 +1340,20 @@ static void svm_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
vmcb_mark_all_dirty(svm->vmcb);
}
+ if (sev_es_guest(svm->vcpu.kvm)) {
+ sev_es_vcpu_load(svm, cpu);
+ } else {
#ifdef CONFIG_X86_64
- rdmsrl(MSR_GS_BASE, to_svm(vcpu)->host.gs_base);
+ rdmsrl(MSR_GS_BASE, to_svm(vcpu)->host.gs_base);
#endif
- savesegment(fs, svm->host.fs);
- savesegment(gs, svm->host.gs);
- svm->host.ldt = kvm_read_ldt();
+ savesegment(fs, svm->host.fs);
+ savesegment(gs, svm->host.gs);
+ svm->host.ldt = kvm_read_ldt();
- for (i = 0; i < NR_HOST_SAVE_USER_MSRS; i++)
- rdmsrl(host_save_user_msrs[i], svm->host_user_msrs[i]);
+ for (i = 0; i < NR_HOST_SAVE_USER_MSRS; i++)
+ rdmsrl(host_save_user_msrs[i].index,
+ svm->host_user_msrs[i]);
+ }
if (static_cpu_has(X86_FEATURE_TSCRATEMSR)) {
u64 tsc_ratio = vcpu->arch.tsc_scaling_ratio;
@@ -1376,19 +1381,24 @@ static void svm_vcpu_put(struct kvm_vcpu *vcpu)
avic_vcpu_put(vcpu);
++vcpu->stat.host_state_reload;
- kvm_load_ldt(svm->host.ldt);
+ if (sev_es_guest(svm->vcpu.kvm)) {
+ sev_es_vcpu_put(svm);
+ } else {
+ kvm_load_ldt(svm->host.ldt);
#ifdef CONFIG_X86_64
- loadsegment(fs, svm->host.fs);
- wrmsrl(MSR_KERNEL_GS_BASE, current->thread.gsbase);
- load_gs_index(svm->host.gs);
+ loadsegment(fs, svm->host.fs);
+ wrmsrl(MSR_KERNEL_GS_BASE, current->thread.gsbase);
+ load_gs_index(svm->host.gs);
#else
#ifdef CONFIG_X86_32_LAZY_GS
- loadsegment(gs, svm->host.gs);
+ loadsegment(gs, svm->host.gs);
#endif
#endif
- for (i = 0; i < NR_HOST_SAVE_USER_MSRS; i++)
- wrmsrl(host_save_user_msrs[i], svm->host_user_msrs[i]);
+ for (i = 0; i < NR_HOST_SAVE_USER_MSRS; i++)
+ wrmsrl(host_save_user_msrs[i].index,
+ svm->host_user_msrs[i]);
+ }
}
static unsigned long svm_get_rflags(struct kvm_vcpu *vcpu)
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 465e14a7146f..0812d70085d7 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -23,15 +23,23 @@
#define __sme_page_pa(x) __sme_set(page_to_pfn(x) << PAGE_SHIFT)
-static const u32 host_save_user_msrs[] = {
+static const struct svm_host_save_msrs {
+ u32 index; /* Index of the MSR */
+ bool sev_es_restored; /* True if MSR is restored on SEV-ES VMEXIT */
+} host_save_user_msrs[] = {
#ifdef CONFIG_X86_64
- MSR_STAR, MSR_LSTAR, MSR_CSTAR, MSR_SYSCALL_MASK, MSR_KERNEL_GS_BASE,
- MSR_FS_BASE,
+ { .index = MSR_STAR, .sev_es_restored = true },
+ { .index = MSR_LSTAR, .sev_es_restored = true },
+ { .index = MSR_CSTAR, .sev_es_restored = true },
+ { .index = MSR_SYSCALL_MASK, .sev_es_restored = true },
+ { .index = MSR_KERNEL_GS_BASE, .sev_es_restored = true },
+ { .index = MSR_FS_BASE, .sev_es_restored = true },
#endif
- MSR_IA32_SYSENTER_CS, MSR_IA32_SYSENTER_ESP, MSR_IA32_SYSENTER_EIP,
- MSR_TSC_AUX,
+ { .index = MSR_IA32_SYSENTER_CS, .sev_es_restored = true },
+ { .index = MSR_IA32_SYSENTER_ESP, .sev_es_restored = true },
+ { .index = MSR_IA32_SYSENTER_EIP, .sev_es_restored = true },
+ { .index = MSR_TSC_AUX, .sev_es_restored = false },
};
-
#define NR_HOST_SAVE_USER_MSRS ARRAY_SIZE(host_save_user_msrs)
#define MSRPM_OFFSETS 16
@@ -573,6 +581,8 @@ int sev_es_string_io(struct vcpu_svm *svm, int size, unsigned int port, int in);
void sev_vcpu_deliver_sipi_vector(struct kvm_vcpu *vcpu, u8 vector);
void sev_es_init_vmcb(struct vcpu_svm *svm);
void sev_es_create_vcpu(struct vcpu_svm *svm);
+void sev_es_vcpu_load(struct vcpu_svm *svm, int cpu);
+void sev_es_vcpu_put(struct vcpu_svm *svm);
/* VMSA Accessor functions */
--
2.28.0
next prev parent reply other threads:[~2020-09-14 20:25 UTC|newest]
Thread overview: 87+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-14 20:15 [RFC PATCH 00/35] SEV-ES hypervisor support Tom Lendacky
2020-09-14 20:15 ` [RFC PATCH 01/35] KVM: SVM: Remove the call to sev_platform_status() during setup Tom Lendacky
2020-09-14 20:15 ` [RFC PATCH 02/35] KVM: SVM: Add support for SEV-ES capability in KVM Tom Lendacky
2020-09-14 20:15 ` [RFC PATCH 03/35] KVM: SVM: Add indirect access to the VM save area Tom Lendacky
2020-09-14 20:15 ` [RFC PATCH 04/35] KVM: SVM: Make GHCB accessor functions available to the hypervisor Tom Lendacky
2020-09-14 20:15 ` [RFC PATCH 05/35] KVM: SVM: Add initial support for SEV-ES GHCB access to KVM Tom Lendacky
[not found] ` <20200914205801.GA7084@sjchrist-ice>
2020-09-15 13:24 ` Tom Lendacky
2020-09-15 16:28 ` Sean Christopherson
2020-09-16 14:54 ` Tom Lendacky
2020-09-14 20:15 ` [RFC PATCH 06/35] KVM: SVM: Add required changes to support intercepts under SEV-ES Tom Lendacky
2020-09-14 20:15 ` [RFC PATCH 07/35] KVM: SVM: Modify DRx register intercepts for an SEV-ES guest Tom Lendacky
2020-09-14 20:15 ` [RFC PATCH 08/35] KVM: SVM: Prevent debugging under SEV-ES Tom Lendacky
2020-09-14 21:26 ` Sean Christopherson
2020-09-15 13:37 ` Tom Lendacky
2020-09-15 16:30 ` Sean Christopherson
2020-09-15 20:13 ` Tom Lendacky
2020-09-16 15:11 ` Tom Lendacky
2020-09-16 16:02 ` Sean Christopherson
2020-09-16 16:38 ` Tom Lendacky
2020-09-16 16:49 ` Sean Christopherson
2020-09-16 20:27 ` Tom Lendacky
2020-09-16 22:50 ` Sean Christopherson
2020-09-17 16:27 ` Tom Lendacky
2020-09-14 20:15 ` [RFC PATCH 09/35] KVM: SVM: Do not emulate MMIO " Tom Lendacky
2020-09-14 21:33 ` Sean Christopherson
2020-09-15 13:38 ` Tom Lendacky
2020-09-14 20:15 ` [RFC PATCH 10/35] KVM: SVM: Cannot re-initialize the VMCB after shutdown with SEV-ES Tom Lendacky
2020-09-14 20:15 ` [RFC PATCH 11/35] KVM: SVM: Prepare for SEV-ES exit handling in the sev.c file Tom Lendacky
[not found] ` <20200915172148.GE8420@sjchrist-ice>
2020-09-16 16:22 ` Tom Lendacky
2020-09-14 20:15 ` [RFC PATCH 12/35] KVM: SVM: Add initial support for a VMGEXIT VMEXIT Tom Lendacky
2020-09-14 20:15 ` [RFC PATCH 13/35] KVM: SVM: Create trace events for VMGEXIT processing Tom Lendacky
2020-09-14 20:15 ` [RFC PATCH 14/35] KVM: SVM: Add support for SEV-ES GHCB MSR protocol function 0x002 Tom Lendacky
2020-09-14 20:15 ` [RFC PATCH 15/35] KVM: SVM: Add support for SEV-ES GHCB MSR protocol function 0x004 Tom Lendacky
2020-09-14 20:15 ` [RFC PATCH 16/35] KVM: SVM: Add support for SEV-ES GHCB MSR protocol function 0x100 Tom Lendacky
2020-09-14 20:15 ` [RFC PATCH 17/35] KVM: SVM: Create trace events for VMGEXIT MSR protocol processing Tom Lendacky
2020-09-14 20:15 ` [RFC PATCH 18/35] KVM: SVM: Support MMIO for an SEV-ES guest Tom Lendacky
2020-09-14 20:15 ` [RFC PATCH 19/35] KVM: SVM: Support port IO operations " Tom Lendacky
2020-09-14 20:15 ` [RFC PATCH 20/35] KVM: SVM: Add SEV/SEV-ES support for intercepting INVD Tom Lendacky
2020-09-14 22:00 ` Sean Christopherson
2020-09-15 15:08 ` Tom Lendacky
2020-09-14 20:15 ` [RFC PATCH 21/35] KVM: SVM: Add support for EFER write traps for an SEV-ES guest Tom Lendacky
[not found] ` <20200914220800.GI7192@sjchrist-ice>
2020-09-15 15:45 ` Tom Lendacky
2020-09-14 20:15 ` [RFC PATCH 22/35] KVM: SVM: Add support for CR0 " Tom Lendacky
2020-09-14 22:13 ` Sean Christopherson
2020-09-15 15:56 ` Tom Lendacky
2020-11-30 18:15 ` Paolo Bonzini
2020-09-14 20:15 ` [RFC PATCH 23/35] KVM: SVM: Add support for CR4 " Tom Lendacky
2020-09-14 22:16 ` Sean Christopherson
2020-11-30 18:16 ` Paolo Bonzini
2020-09-14 20:15 ` [RFC PATCH 24/35] KVM: SVM: Add support for CR8 " Tom Lendacky
2020-09-14 22:19 ` Sean Christopherson
2020-09-15 15:57 ` Tom Lendacky
2020-09-14 20:15 ` [RFC PATCH 25/35] KVM: x86: Update __get_sregs() / __set_sregs() to support SEV-ES Tom Lendacky
2020-09-14 21:37 ` Sean Christopherson
2020-09-15 14:19 ` Tom Lendacky
2020-09-15 16:33 ` Sean Christopherson
2020-09-15 20:37 ` Tom Lendacky
2020-09-15 22:44 ` Sean Christopherson
2020-11-30 18:28 ` Paolo Bonzini
2020-11-30 19:39 ` Sean Christopherson
2020-09-14 20:15 ` [RFC PATCH 26/35] KVM: SVM: Guest FPU state save/restore not needed for SEV-ES guest Tom Lendacky
[not found] ` <20200914213917.GD7192@sjchrist-ice>
2020-09-15 14:25 ` Tom Lendacky
2020-09-15 16:34 ` Sean Christopherson
2020-09-14 20:15 ` [RFC PATCH 27/35] KVM: SVM: Add support for booting APs for an " Tom Lendacky
2020-09-14 20:15 ` [RFC PATCH 28/35] KVM: X86: Update kvm_skip_emulated_instruction() " Tom Lendacky
2020-09-14 21:51 ` Sean Christopherson
2020-09-15 14:57 ` Tom Lendacky
2020-09-14 20:15 ` [RFC PATCH 29/35] KVM: SVM: Add NMI support " Tom Lendacky
2020-09-14 20:15 ` [RFC PATCH 30/35] KVM: SVM: Set the encryption mask for the SVM host save area Tom Lendacky
2020-09-14 20:15 ` [RFC PATCH 31/35] KVM: SVM: Update ASID allocation to support SEV-ES guests Tom Lendacky
2020-09-14 20:15 ` [RFC PATCH 32/35] KVM: SVM: Provide support for SEV-ES vCPU creation/loading Tom Lendacky
2020-09-14 20:15 ` Tom Lendacky [this message]
2020-09-14 20:15 ` [RFC PATCH 34/35] KVM: SVM: Provide an updated VMRUN invocation for SEV-ES guests Tom Lendacky
2020-09-14 20:15 ` [RFC PATCH 35/35] KVM: SVM: Provide support to launch and run an SEV-ES guest Tom Lendacky
2020-09-14 22:59 ` [RFC PATCH 00/35] SEV-ES hypervisor support Sean Christopherson
2020-09-15 17:22 ` Tom Lendacky
2020-09-15 17:32 ` Sean Christopherson
2020-09-15 20:05 ` Brijesh Singh
2020-09-16 0:19 ` Sean Christopherson
2020-10-13 20:26 ` Tom Lendacky
2020-11-30 15:31 ` Paolo Bonzini
2020-11-30 16:06 ` Tom Lendacky
2020-11-30 18:18 ` Sean Christopherson
2020-11-30 18:14 ` Sean Christopherson
2020-11-30 18:35 ` Paolo Bonzini
2020-11-30 19:35 ` Sean Christopherson
2020-11-30 20:24 ` Paolo Bonzini
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