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Message-Id: <9d61daf0ffda496703717218f415cdc8fd487100.1607620209.git.thomas.lendacky@amd.com>
Date: Thu, 10 Dec 2020 11:09:54 -0600
From: Tom Lendacky <thomas.lendacky@....com>
To: kvm@...r.kernel.org, linux-kernel@...r.kernel.org, x86@...nel.org
Cc: Paolo Bonzini <pbonzini@...hat.com>,
Jim Mattson <jmattson@...gle.com>,
Joerg Roedel <joro@...tes.org>,
Sean Christopherson <seanjc@...gle.com>,
Vitaly Kuznetsov <vkuznets@...hat.com>,
Wanpeng Li <wanpengli@...cent.com>,
Borislav Petkov <bp@...en8.de>, Ingo Molnar <mingo@...hat.com>,
Thomas Gleixner <tglx@...utronix.de>,
Brijesh Singh <brijesh.singh@....com>,
kernel test robot <lkp@...el.com>
Subject: [PATCH v5 19/34] KVM: SVM: Support string IO operations for an SEV-ES guest
From: Tom Lendacky <thomas.lendacky@....com>
For an SEV-ES guest, string-based port IO is performed to a shared
(un-encrypted) page so that both the hypervisor and guest can read or
write to it and each see the contents.
For string-based port IO operations, invoke SEV-ES specific routines that
can complete the operation using common KVM port IO support.
[ set but not used variable ]
Reported-by: kernel test robot <lkp@...el.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@....com>
---
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kvm/svm/sev.c | 18 +++++++++--
arch/x86/kvm/svm/svm.c | 11 +++++--
arch/x86/kvm/svm/svm.h | 1 +
arch/x86/kvm/x86.c | 54 +++++++++++++++++++++++++++++++++
arch/x86/kvm/x86.h | 3 ++
6 files changed, 83 insertions(+), 5 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 8cf6b0493d49..26f937111226 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -614,6 +614,7 @@ struct kvm_vcpu_arch {
struct kvm_pio_request pio;
void *pio_data;
+ void *guest_ins_data;
u8 event_exit_inst_len;
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 63f20be4bc69..a7531de760b5 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -1406,9 +1406,14 @@ static int sev_es_validate_vmgexit(struct vcpu_svm *svm)
case SVM_EXIT_INVD:
break;
case SVM_EXIT_IOIO:
- if (!(ghcb_get_sw_exit_info_1(ghcb) & SVM_IOIO_TYPE_MASK))
- if (!ghcb_rax_is_valid(ghcb))
+ if (ghcb_get_sw_exit_info_1(ghcb) & SVM_IOIO_STR_MASK) {
+ if (!ghcb_sw_scratch_is_valid(ghcb))
goto vmgexit_err;
+ } else {
+ if (!(ghcb_get_sw_exit_info_1(ghcb) & SVM_IOIO_TYPE_MASK))
+ if (!ghcb_rax_is_valid(ghcb))
+ goto vmgexit_err;
+ }
break;
case SVM_EXIT_MSR:
if (!ghcb_rcx_is_valid(ghcb))
@@ -1776,3 +1781,12 @@ int sev_handle_vmgexit(struct vcpu_svm *svm)
return ret;
}
+
+int sev_es_string_io(struct vcpu_svm *svm, int size, unsigned int port, int in)
+{
+ if (!setup_vmgexit_scratch(svm, in, svm->vmcb->control.exit_info_2))
+ return -EINVAL;
+
+ return kvm_sev_es_string_io(&svm->vcpu, size, port,
+ svm->ghcb_sa, svm->ghcb_sa_len, in);
+}
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index ad1ec6ad558e..32502c4b091d 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -2058,11 +2058,16 @@ static int io_interception(struct vcpu_svm *svm)
++svm->vcpu.stat.io_exits;
string = (io_info & SVM_IOIO_STR_MASK) != 0;
in = (io_info & SVM_IOIO_TYPE_MASK) != 0;
- if (string)
- return kvm_emulate_instruction(vcpu, 0);
-
port = io_info >> 16;
size = (io_info & SVM_IOIO_SIZE_MASK) >> SVM_IOIO_SIZE_SHIFT;
+
+ if (string) {
+ if (sev_es_guest(vcpu->kvm))
+ return sev_es_string_io(svm, size, port, in);
+ else
+ return kvm_emulate_instruction(vcpu, 0);
+ }
+
svm->next_rip = svm->vmcb->control.exit_info_2;
return kvm_fast_pio(&svm->vcpu, size, port, in);
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 9019ad6a8138..b3f03dede6ac 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -573,5 +573,6 @@ void __init sev_hardware_setup(void);
void sev_hardware_teardown(void);
void sev_free_vcpu(struct kvm_vcpu *vcpu);
int sev_handle_vmgexit(struct vcpu_svm *svm);
+int sev_es_string_io(struct vcpu_svm *svm, int size, unsigned int port, int in);
#endif
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 78e8c8b36f9b..fcd862f5a2b4 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -10790,6 +10790,10 @@ int kvm_arch_interrupt_allowed(struct kvm_vcpu *vcpu)
unsigned long kvm_get_linear_rip(struct kvm_vcpu *vcpu)
{
+ /* Can't read the RIP when guest state is protected, just return 0 */
+ if (vcpu->arch.guest_state_protected)
+ return 0;
+
if (is_64_bit_mode(vcpu))
return kvm_rip_read(vcpu);
return (u32)(get_segment_base(vcpu, VCPU_SREG_CS) +
@@ -11422,6 +11426,56 @@ int kvm_sev_es_mmio_read(struct kvm_vcpu *vcpu, gpa_t gpa, unsigned int bytes,
}
EXPORT_SYMBOL_GPL(kvm_sev_es_mmio_read);
+static int complete_sev_es_emulated_ins(struct kvm_vcpu *vcpu)
+{
+ memcpy(vcpu->arch.guest_ins_data, vcpu->arch.pio_data,
+ vcpu->arch.pio.count * vcpu->arch.pio.size);
+ vcpu->arch.pio.count = 0;
+
+ return 1;
+}
+
+static int kvm_sev_es_outs(struct kvm_vcpu *vcpu, unsigned int size,
+ unsigned int port, void *data, unsigned int count)
+{
+ int ret;
+
+ ret = emulator_pio_out_emulated(vcpu->arch.emulate_ctxt, size, port,
+ data, count);
+ if (ret)
+ return ret;
+
+ vcpu->arch.pio.count = 0;
+
+ return 0;
+}
+
+static int kvm_sev_es_ins(struct kvm_vcpu *vcpu, unsigned int size,
+ unsigned int port, void *data, unsigned int count)
+{
+ int ret;
+
+ ret = emulator_pio_in_emulated(vcpu->arch.emulate_ctxt, size, port,
+ data, count);
+ if (ret) {
+ vcpu->arch.pio.count = 0;
+ } else {
+ vcpu->arch.guest_ins_data = data;
+ vcpu->arch.complete_userspace_io = complete_sev_es_emulated_ins;
+ }
+
+ return 0;
+}
+
+int kvm_sev_es_string_io(struct kvm_vcpu *vcpu, unsigned int size,
+ unsigned int port, void *data, unsigned int count,
+ int in)
+{
+ return in ? kvm_sev_es_ins(vcpu, size, port, data, count)
+ : kvm_sev_es_outs(vcpu, size, port, data, count);
+}
+EXPORT_SYMBOL_GPL(kvm_sev_es_string_io);
+
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_exit);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_fast_mmio);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_inj_virq);
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index 804369fe45e3..0e8fe766a4c5 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -411,5 +411,8 @@ int kvm_sev_es_mmio_write(struct kvm_vcpu *vcpu, gpa_t src, unsigned int bytes,
void *dst);
int kvm_sev_es_mmio_read(struct kvm_vcpu *vcpu, gpa_t src, unsigned int bytes,
void *dst);
+int kvm_sev_es_string_io(struct kvm_vcpu *vcpu, unsigned int size,
+ unsigned int port, void *data, unsigned int count,
+ int in);
#endif
--
2.28.0
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