Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "ARM:

   - Generalized infrastructure for 'writable' ID registers, effectively
     allowing userspace to opt-out of certain vCPU features for its
     guest

   - Optimization for vSGI injection, opportunistically compressing
     MPIDR to vCPU mapping into a table

   - Improvements to KVM's PMU emulation, allowing userspace to select
     the number of PMCs available to a VM

   - Guest support for memory operation instructions (FEAT_MOPS)

   - Cleanups to handling feature flags in KVM_ARM_VCPU_INIT, squashing
     bugs and getting rid of useless code

   - Changes to the way the SMCCC filter is constructed, avoiding wasted
     memory allocations when not in use

   - Load the stage-2 MMU context at vcpu_load() for VHE systems,
     reducing the overhead of errata mitigations

   - Miscellaneous kernel and selftest fixes

  LoongArch:

   - New architecture for kvm.

     The hardware uses the same model as x86, s390 and RISC-V, where
     guest/host mode is orthogonal to supervisor/user mode. The
     virtualization extensions are very similar to MIPS, therefore the
     code also has some similarities but it's been cleaned up to avoid
     some of the historical bogosities that are found in arch/mips. The
     kernel emulates MMU, timer and CSR accesses, while interrupt
     controllers are only emulated in userspace, at least for now.

  RISC-V:

   - Support for the Smstateen and Zicond extensions

   - Support for virtualizing senvcfg

   - Support for virtualized SBI debug console (DBCN)

  S390:

   - Nested page table management can be monitored through tracepoints
     and statistics

  x86:

   - Fix incorrect handling of VMX posted interrupt descriptor in
     KVM_SET_LAPIC, which could result in a dropped timer IRQ

   - Avoid WARN on systems with Intel IPI virtualization

   - Add CONFIG_KVM_MAX_NR_VCPUS, to allow supporting up to 4096 vCPUs
     without forcing more common use cases to eat the extra memory
     overhead.

   - Add virtualization support for AMD SRSO mitigation (IBPB_BRTYPE and
     SBPB, aka Selective Branch Predictor Barrier).

   - Fix a bug where restoring a vCPU snapshot that was taken within 1
     second of creating the original vCPU would cause KVM to try to
     synchronize the vCPU's TSC and thus clobber the correct TSC being
     set by userspace.

   - Compute guest wall clock using a single TSC read to avoid
     generating an inaccurate time, e.g. if the vCPU is preempted
     between multiple TSC reads.

   - "Virtualize" HWCR.TscFreqSel to make Linux guests happy, which
     complain about a "Firmware Bug" if the bit isn't set for select
     F/M/S combos. Likewise "virtualize" (ignore) MSR_AMD64_TW_CFG to
     appease Windows Server 2022.

   - Don't apply side effects to Hyper-V's synthetic timer on writes
     from userspace to fix an issue where the auto-enable behavior can
     trigger spurious interrupts, i.e. do auto-enabling only for guest
     writes.

   - Remove an unnecessary kick of all vCPUs when synchronizing the
     dirty log without PML enabled.

   - Advertise "support" for non-serializing FS/GS base MSR writes as
     appropriate.

   - Harden the fast page fault path to guard against encountering an
     invalid root when walking SPTEs.

   - Omit "struct kvm_vcpu_xen" entirely when CONFIG_KVM_XEN=n.

   - Use the fast path directly from the timer callback when delivering
     Xen timer events, instead of waiting for the next iteration of the
     run loop. This was not done so far because previously proposed code
     had races, but now care is taken to stop the hrtimer at critical
     points such as restarting the timer or saving the timer information
     for userspace.

   - Follow the lead of upstream Xen and ignore the VCPU_SSHOTTMR_future
     flag.

   - Optimize injection of PMU interrupts that are simultaneous with
     NMIs.

   - Usual handful of fixes for typos and other warts.

  x86 - MTRR/PAT fixes and optimizations:

   - Clean up code that deals with honoring guest MTRRs when the VM has
     non-coherent DMA and host MTRRs are ignored, i.e. EPT is enabled.

   - Zap EPT entries when non-coherent DMA assignment stops/start to
     prevent using stale entries with the wrong memtype.

   - Don't ignore guest PAT for CR0.CD=1 && KVM_X86_QUIRK_CD_NW_CLEARED=y

     This was done as a workaround for virtual machine BIOSes that did
     not bother to clear CR0.CD (because ancient KVM/QEMU did not bother
     to set it, in turn), and there's zero reason to extend the quirk to
     also ignore guest PAT.

  x86 - SEV fixes:

   - Report KVM_EXIT_SHUTDOWN instead of EINVAL if KVM intercepts
     SHUTDOWN while running an SEV-ES guest.

   - Clean up the recognition of emulation failures on SEV guests, when
     KVM would like to "skip" the instruction but it had already been
     partially emulated. This makes it possible to drop a hack that
     second guessed the (insufficient) information provided by the
     emulator, and just do the right thing.

  Documentation:

   - Various updates and fixes, mostly for x86

   - MTRR and PAT fixes and optimizations"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (164 commits)
  KVM: selftests: Avoid using forced target for generating arm64 headers
  tools headers arm64: Fix references to top srcdir in Makefile
  KVM: arm64: Add tracepoint for MMIO accesses where ISV==0
  KVM: arm64: selftest: Perform ISB before reading PAR_EL1
  KVM: arm64: selftest: Add the missing .guest_prepare()
  KVM: arm64: Always invalidate TLB for stage-2 permission faults
  KVM: x86: Service NMI requests after PMI requests in VM-Enter path
  KVM: arm64: Handle AArch32 SPSR_{irq,abt,und,fiq} as RAZ/WI
  KVM: arm64: Do not let a L1 hypervisor access the *32_EL2 sysregs
  KVM: arm64: Refine _EL2 system register list that require trap reinjection
  arm64: Add missing _EL2 encodings
  arm64: Add missing _EL12 encodings
  KVM: selftests: aarch64: vPMU test for validating user accesses
  KVM: selftests: aarch64: vPMU register test for unimplemented counters
  KVM: selftests: aarch64: vPMU register test for implemented counters
  KVM: selftests: aarch64: Introduce vpmu_counter_access test
  tools: Import arm_pmuv3.h
  KVM: arm64: PMU: Allow userspace to limit PMCR_EL0.N for the guest
  KVM: arm64: Sanitize PM{C,I}NTEN{SET,CLR}, PMOVS{SET,CLR} before first run
  KVM: arm64: Add {get,set}_user for PM{C,I}NTEN{SET,CLR}, PMOVS{SET,CLR}
  ...

11 files changed, 261 insertions, 46 deletions

diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h
index 777cb8299551..306a19a5509c 100644
--- a/arch/riscv/include/asm/csr.h
+++ b/arch/riscv/include/asm/csr.h
@@ -203,6 +203,18 @@
 #define ENVCFG_CBIE_INV			_AC(0x3, UL)
 #define ENVCFG_FIOM			_AC(0x1, UL)
 
+/* Smstateen bits */
+#define SMSTATEEN0_AIA_IMSIC_SHIFT	58
+#define SMSTATEEN0_AIA_IMSIC		(_ULL(1) << SMSTATEEN0_AIA_IMSIC_SHIFT)
+#define SMSTATEEN0_AIA_SHIFT		59
+#define SMSTATEEN0_AIA			(_ULL(1) << SMSTATEEN0_AIA_SHIFT)
+#define SMSTATEEN0_AIA_ISEL_SHIFT	60
+#define SMSTATEEN0_AIA_ISEL		(_ULL(1) << SMSTATEEN0_AIA_ISEL_SHIFT)
+#define SMSTATEEN0_HSENVCFG_SHIFT	62
+#define SMSTATEEN0_HSENVCFG		(_ULL(1) << SMSTATEEN0_HSENVCFG_SHIFT)
+#define SMSTATEEN0_SSTATEEN0_SHIFT	63
+#define SMSTATEEN0_SSTATEEN0		(_ULL(1) << SMSTATEEN0_SSTATEEN0_SHIFT)
+
 /* symbolic CSR names: */
 #define CSR_CYCLE		0xc00
 #define CSR_TIME		0xc01
@@ -275,6 +287,8 @@
 #define CSR_SIE			0x104
 #define CSR_STVEC		0x105
 #define CSR_SCOUNTEREN		0x106
+#define CSR_SENVCFG		0x10a
+#define CSR_SSTATEEN0		0x10c
 #define CSR_SSCRATCH		0x140
 #define CSR_SEPC		0x141
 #define CSR_SCAUSE		0x142
@@ -349,6 +363,10 @@
 #define CSR_VSIEH		0x214
 #define CSR_VSIPH		0x254
 
+/* Hypervisor stateen CSRs */
+#define CSR_HSTATEEN0		0x60c
+#define CSR_HSTATEEN0H		0x61c
+
 #define CSR_MSTATUS		0x300
 #define CSR_MISA		0x301
 #define CSR_MIDELEG		0x303
diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
index b7b58258f6c7..6fc51c1b34cf 100644
--- a/arch/riscv/include/asm/hwcap.h
+++ b/arch/riscv/include/asm/hwcap.h
@@ -58,6 +58,8 @@
 #define RISCV_ISA_EXT_ZICSR		40
 #define RISCV_ISA_EXT_ZIFENCEI		41
 #define RISCV_ISA_EXT_ZIHPM		42
+#define RISCV_ISA_EXT_SMSTATEEN		43
+#define RISCV_ISA_EXT_ZICOND		44
 
 #define RISCV_ISA_EXT_MAX		64
 
diff --git a/arch/riscv/include/asm/kvm_host.h b/arch/riscv/include/asm/kvm_host.h
index 1ebf20dfbaa6..0eefd9c991ae 100644
--- a/arch/riscv/include/asm/kvm_host.h
+++ b/arch/riscv/include/asm/kvm_host.h
@@ -162,6 +162,16 @@ struct kvm_vcpu_csr {
 	unsigned long hvip;
 	unsigned long vsatp;
 	unsigned long scounteren;
+	unsigned long senvcfg;
+};
+
+struct kvm_vcpu_config {
+	u64 henvcfg;
+	u64 hstateen0;
+};
+
+struct kvm_vcpu_smstateen_csr {
+	unsigned long sstateen0;
 };
 
 struct kvm_vcpu_arch {
@@ -183,6 +193,8 @@ struct kvm_vcpu_arch {
 	unsigned long host_sscratch;
 	unsigned long host_stvec;
 	unsigned long host_scounteren;
+	unsigned long host_senvcfg;
+	unsigned long host_sstateen0;
 
 	/* CPU context of Host */
 	struct kvm_cpu_context host_context;
@@ -193,6 +205,9 @@ struct kvm_vcpu_arch {
 	/* CPU CSR context of Guest VCPU */
 	struct kvm_vcpu_csr guest_csr;
 
+	/* CPU Smstateen CSR context of Guest VCPU */
+	struct kvm_vcpu_smstateen_csr smstateen_csr;
+
 	/* CPU context upon Guest VCPU reset */
 	struct kvm_cpu_context guest_reset_context;
 
@@ -244,6 +259,9 @@ struct kvm_vcpu_arch {
 
 	/* Performance monitoring context */
 	struct kvm_pmu pmu_context;
+
+	/* 'static' configurations which are set only once */
+	struct kvm_vcpu_config cfg;
 };
 
 static inline void kvm_arch_sync_events(struct kvm *kvm) {}
diff --git a/arch/riscv/include/asm/kvm_vcpu_sbi.h b/arch/riscv/include/asm/kvm_vcpu_sbi.h
index cdcf0ff07be7..6a453f7f8b56 100644
--- a/arch/riscv/include/asm/kvm_vcpu_sbi.h
+++ b/arch/riscv/include/asm/kvm_vcpu_sbi.h
@@ -11,7 +11,7 @@
 
 #define KVM_SBI_IMPID 3
 
-#define KVM_SBI_VERSION_MAJOR 1
+#define KVM_SBI_VERSION_MAJOR 2
 #define KVM_SBI_VERSION_MINOR 0
 
 enum kvm_riscv_sbi_ext_status {
@@ -35,6 +35,9 @@ struct kvm_vcpu_sbi_return {
 struct kvm_vcpu_sbi_extension {
 	unsigned long extid_start;
 	unsigned long extid_end;
+
+	bool default_unavail;
+
 	/**
 	 * SBI extension handler. It can be defined for a given extension or group of
 	 * extension. But it should always return linux error codes rather than SBI
@@ -59,6 +62,7 @@ int kvm_riscv_vcpu_get_reg_sbi_ext(struct kvm_vcpu *vcpu,
 const struct kvm_vcpu_sbi_extension *kvm_vcpu_sbi_find_ext(
 				struct kvm_vcpu *vcpu, unsigned long extid);
 int kvm_riscv_vcpu_sbi_ecall(struct kvm_vcpu *vcpu, struct kvm_run *run);
+void kvm_riscv_vcpu_sbi_init(struct kvm_vcpu *vcpu);
 
 #ifdef CONFIG_RISCV_SBI_V01
 extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_v01;
@@ -69,6 +73,7 @@ extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_ipi;
 extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_rfence;
 extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_srst;
 extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_hsm;
+extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_dbcn;
 extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_experimental;
 extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_vendor;
 
diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h
index 5b4a1bf5f439..12dfda6bb924 100644
--- a/arch/riscv/include/asm/sbi.h
+++ b/arch/riscv/include/asm/sbi.h
@@ -30,6 +30,7 @@ enum sbi_ext_id {
 	SBI_EXT_HSM = 0x48534D,
 	SBI_EXT_SRST = 0x53525354,
 	SBI_EXT_PMU = 0x504D55,
+	SBI_EXT_DBCN = 0x4442434E,
 
 	/* Experimentals extensions must lie within this range */
 	SBI_EXT_EXPERIMENTAL_START = 0x08000000,
@@ -236,6 +237,12 @@ enum sbi_pmu_ctr_type {
 /* Flags defined for counter stop function */
 #define SBI_PMU_STOP_FLAG_RESET (1 << 0)
 
+enum sbi_ext_dbcn_fid {
+	SBI_EXT_DBCN_CONSOLE_WRITE = 0,
+	SBI_EXT_DBCN_CONSOLE_READ = 1,
+	SBI_EXT_DBCN_CONSOLE_WRITE_BYTE = 2,
+};
+
 #define SBI_SPEC_VERSION_DEFAULT	0x1
 #define SBI_SPEC_VERSION_MAJOR_SHIFT	24
 #define SBI_SPEC_VERSION_MAJOR_MASK	0x7f
diff --git a/arch/riscv/include/uapi/asm/kvm.h b/arch/riscv/include/uapi/asm/kvm.h
index 992c5e407104..60d3b21dead7 100644
--- a/arch/riscv/include/uapi/asm/kvm.h
+++ b/arch/riscv/include/uapi/asm/kvm.h
@@ -80,6 +80,7 @@ struct kvm_riscv_csr {
 	unsigned long sip;
 	unsigned long satp;
 	unsigned long scounteren;
+	unsigned long senvcfg;
 };
 
 /* AIA CSR registers for KVM_GET_ONE_REG and KVM_SET_ONE_REG */
@@ -93,6 +94,11 @@ struct kvm_riscv_aia_csr {
 	unsigned long iprio2h;
 };
 
+/* Smstateen CSR for KVM_GET_ONE_REG and KVM_SET_ONE_REG */
+struct kvm_riscv_smstateen_csr {
+	unsigned long sstateen0;
+};
+
 /* TIMER registers for KVM_GET_ONE_REG and KVM_SET_ONE_REG */
 struct kvm_riscv_timer {
 	__u64 frequency;
@@ -131,6 +137,8 @@ enum KVM_RISCV_ISA_EXT_ID {
 	KVM_RISCV_ISA_EXT_ZICSR,
 	KVM_RISCV_ISA_EXT_ZIFENCEI,
 	KVM_RISCV_ISA_EXT_ZIHPM,
+	KVM_RISCV_ISA_EXT_SMSTATEEN,
+	KVM_RISCV_ISA_EXT_ZICOND,
 	KVM_RISCV_ISA_EXT_MAX,
 };
 
@@ -148,6 +156,7 @@ enum KVM_RISCV_SBI_EXT_ID {
 	KVM_RISCV_SBI_EXT_PMU,
 	KVM_RISCV_SBI_EXT_EXPERIMENTAL,
 	KVM_RISCV_SBI_EXT_VENDOR,
+	KVM_RISCV_SBI_EXT_DBCN,
 	KVM_RISCV_SBI_EXT_MAX,
 };
 
@@ -178,10 +187,13 @@ enum KVM_RISCV_SBI_EXT_ID {
 #define KVM_REG_RISCV_CSR		(0x03 << KVM_REG_RISCV_TYPE_SHIFT)
 #define KVM_REG_RISCV_CSR_GENERAL	(0x0 << KVM_REG_RISCV_SUBTYPE_SHIFT)
 #define KVM_REG_RISCV_CSR_AIA		(0x1 << KVM_REG_RISCV_SUBTYPE_SHIFT)
+#define KVM_REG_RISCV_CSR_SMSTATEEN	(0x2 << KVM_REG_RISCV_SUBTYPE_SHIFT)
 #define KVM_REG_RISCV_CSR_REG(name)	\
 		(offsetof(struct kvm_riscv_csr, name) / sizeof(unsigned long))
 #define KVM_REG_RISCV_CSR_AIA_REG(name)	\
 	(offsetof(struct kvm_riscv_aia_csr, name) / sizeof(unsigned long))
+#define KVM_REG_RISCV_CSR_SMSTATEEN_REG(name)  \
+	(offsetof(struct kvm_riscv_smstateen_csr, name) / sizeof(unsigned long))
 
 /* Timer registers are mapped as type 4 */
 #define KVM_REG_RISCV_TIMER		(0x04 << KVM_REG_RISCV_TYPE_SHIFT)
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index 1cfbba65d11a..e3803822ab5a 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -167,6 +167,7 @@ const struct riscv_isa_ext_data riscv_isa_ext[] = {
 	__RISCV_ISA_EXT_DATA(zicbom, RISCV_ISA_EXT_ZICBOM),
 	__RISCV_ISA_EXT_DATA(zicboz, RISCV_ISA_EXT_ZICBOZ),
 	__RISCV_ISA_EXT_DATA(zicntr, RISCV_ISA_EXT_ZICNTR),
+	__RISCV_ISA_EXT_DATA(zicond, RISCV_ISA_EXT_ZICOND),
 	__RISCV_ISA_EXT_DATA(zicsr, RISCV_ISA_EXT_ZICSR),
 	__RISCV_ISA_EXT_DATA(zifencei, RISCV_ISA_EXT_ZIFENCEI),
 	__RISCV_ISA_EXT_DATA(zihintpause, RISCV_ISA_EXT_ZIHINTPAUSE),
@@ -175,6 +176,7 @@ const struct riscv_isa_ext_data riscv_isa_ext[] = {
 	__RISCV_ISA_EXT_DATA(zbb, RISCV_ISA_EXT_ZBB),
 	__RISCV_ISA_EXT_DATA(zbs, RISCV_ISA_EXT_ZBS),
 	__RISCV_ISA_EXT_DATA(smaia, RISCV_ISA_EXT_SMAIA),
+	__RISCV_ISA_EXT_DATA(smstateen, RISCV_ISA_EXT_SMSTATEEN),
 	__RISCV_ISA_EXT_DATA(ssaia, RISCV_ISA_EXT_SSAIA),
 	__RISCV_ISA_EXT_DATA(sscofpmf, RISCV_ISA_EXT_SSCOFPMF),
 	__RISCV_ISA_EXT_DATA(sstc, RISCV_ISA_EXT_SSTC),
diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c
index 82229db1ce73..e087c809073c 100644
--- a/arch/riscv/kvm/vcpu.c
+++ b/arch/riscv/kvm/vcpu.c
@@ -141,6 +141,12 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
 	if (rc)
 		return rc;
 
+	/*
+	 * Setup SBI extensions
+	 * NOTE: This must be the last thing to be initialized.
+	 */
+	kvm_riscv_vcpu_sbi_init(vcpu);
+
 	/* Reset VCPU */
 	kvm_riscv_reset_vcpu(vcpu);
 
@@ -471,31 +477,38 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
 	return -EINVAL;
 }
 
-static void kvm_riscv_vcpu_update_config(const unsigned long *isa)
+static void kvm_riscv_vcpu_setup_config(struct kvm_vcpu *vcpu)
 {
-	u64 henvcfg = 0;
+	const unsigned long *isa = vcpu->arch.isa;
+	struct kvm_vcpu_config *cfg = &vcpu->arch.cfg;
 
 	if (riscv_isa_extension_available(isa, SVPBMT))
-		henvcfg |= ENVCFG_PBMTE;
+		cfg->henvcfg |= ENVCFG_PBMTE;
 
 	if (riscv_isa_extension_available(isa, SSTC))
-		henvcfg |= ENVCFG_STCE;
+		cfg->henvcfg |= ENVCFG_STCE;
 
 	if (riscv_isa_extension_available(isa, ZICBOM))
-		henvcfg |= (ENVCFG_CBIE | ENVCFG_CBCFE);
+		cfg->henvcfg |= (ENVCFG_CBIE | ENVCFG_CBCFE);
 
 	if (riscv_isa_extension_available(isa, ZICBOZ))
-		henvcfg |= ENVCFG_CBZE;
-
-	csr_write(CSR_HENVCFG, henvcfg);
-#ifdef CONFIG_32BIT
-	csr_write(CSR_HENVCFGH, henvcfg >> 32);
-#endif
+		cfg->henvcfg |= ENVCFG_CBZE;
+
+	if (riscv_has_extension_unlikely(RISCV_ISA_EXT_SMSTATEEN)) {
+		cfg->hstateen0 |= SMSTATEEN0_HSENVCFG;
+		if (riscv_isa_extension_available(isa, SSAIA))
+			cfg->hstateen0 |= SMSTATEEN0_AIA_IMSIC |
+					  SMSTATEEN0_AIA |
+					  SMSTATEEN0_AIA_ISEL;
+		if (riscv_isa_extension_available(isa, SMSTATEEN))
+			cfg->hstateen0 |= SMSTATEEN0_SSTATEEN0;
+	}
 }
 
 void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 {
 	struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr;
+	struct kvm_vcpu_config *cfg = &vcpu->arch.cfg;
 
 	csr_write(CSR_VSSTATUS, csr->vsstatus);
 	csr_write(CSR_VSIE, csr->vsie);
@@ -506,8 +519,14 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 	csr_write(CSR_VSTVAL, csr->vstval);
 	csr_write(CSR_HVIP, csr->hvip);
 	csr_write(CSR_VSATP, csr->vsatp);
-
-	kvm_riscv_vcpu_update_config(vcpu->arch.isa);
+	csr_write(CSR_HENVCFG, cfg->henvcfg);
+	if (IS_ENABLED(CONFIG_32BIT))
+		csr_write(CSR_HENVCFGH, cfg->henvcfg >> 32);
+	if (riscv_has_extension_unlikely(RISCV_ISA_EXT_SMSTATEEN)) {
+		csr_write(CSR_HSTATEEN0, cfg->hstateen0);
+		if (IS_ENABLED(CONFIG_32BIT))
+			csr_write(CSR_HSTATEEN0H, cfg->hstateen0 >> 32);
+	}
 
 	kvm_riscv_gstage_update_hgatp(vcpu);
 
@@ -606,6 +625,32 @@ static void kvm_riscv_update_hvip(struct kvm_vcpu *vcpu)
 	kvm_riscv_vcpu_aia_update_hvip(vcpu);
 }
 
+static __always_inline void kvm_riscv_vcpu_swap_in_guest_state(struct kvm_vcpu *vcpu)
+{
+	struct kvm_vcpu_smstateen_csr *smcsr = &vcpu->arch.smstateen_csr;
+	struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr;
+	struct kvm_vcpu_config *cfg = &vcpu->arch.cfg;
+
+	vcpu->arch.host_senvcfg = csr_swap(CSR_SENVCFG, csr->senvcfg);
+	if (riscv_has_extension_unlikely(RISCV_ISA_EXT_SMSTATEEN) &&
+	    (cfg->hstateen0 & SMSTATEEN0_SSTATEEN0))
+		vcpu->arch.host_sstateen0 = csr_swap(CSR_SSTATEEN0,
+						     smcsr->sstateen0);
+}
+
+static __always_inline void kvm_riscv_vcpu_swap_in_host_state(struct kvm_vcpu *vcpu)
+{
+	struct kvm_vcpu_smstateen_csr *smcsr = &vcpu->arch.smstateen_csr;
+	struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr;
+	struct kvm_vcpu_config *cfg = &vcpu->arch.cfg;
+
+	csr->senvcfg = csr_swap(CSR_SENVCFG, vcpu->arch.host_senvcfg);
+	if (riscv_has_extension_unlikely(RISCV_ISA_EXT_SMSTATEEN) &&
+	    (cfg->hstateen0 & SMSTATEEN0_SSTATEEN0))
+		smcsr->sstateen0 = csr_swap(CSR_SSTATEEN0,
+					    vcpu->arch.host_sstateen0);
+}
+
 /*
  * Actually run the vCPU, entering an RCU extended quiescent state (EQS) while
  * the vCPU is running.
@@ -615,10 +660,12 @@ static void kvm_riscv_update_hvip(struct kvm_vcpu *vcpu)
  */
 static void noinstr kvm_riscv_vcpu_enter_exit(struct kvm_vcpu *vcpu)
 {
+	kvm_riscv_vcpu_swap_in_guest_state(vcpu);
 	guest_state_enter_irqoff();
 	__kvm_riscv_switch_to(&vcpu->arch);
 	vcpu->arch.last_exit_cpu = vcpu->cpu;
 	guest_state_exit_irqoff();
+	kvm_riscv_vcpu_swap_in_host_state(vcpu);
 }
 
 int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
@@ -627,6 +674,9 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
 	struct kvm_cpu_trap trap;
 	struct kvm_run *run = vcpu->run;
 
+	if (!vcpu->arch.ran_atleast_once)
+		kvm_riscv_vcpu_setup_config(vcpu);
+
 	/* Mark this VCPU ran at least once */
 	vcpu->arch.ran_atleast_once = true;
 
diff --git a/arch/riscv/kvm/vcpu_onereg.c b/arch/riscv/kvm/vcpu_onereg.c
index b7e0e03c69b1..c6ebce6126b5 100644
--- a/arch/riscv/kvm/vcpu_onereg.c
+++ b/arch/riscv/kvm/vcpu_onereg.c
@@ -34,6 +34,7 @@ static const unsigned long kvm_isa_ext_arr[] = {
 	[KVM_RISCV_ISA_EXT_M] = RISCV_ISA_EXT_m,
 	[KVM_RISCV_ISA_EXT_V] = RISCV_ISA_EXT_v,
 	/* Multi letter extensions (alphabetically sorted) */
+	KVM_ISA_EXT_ARR(SMSTATEEN),
 	KVM_ISA_EXT_ARR(SSAIA),
 	KVM_ISA_EXT_ARR(SSTC),
 	KVM_ISA_EXT_ARR(SVINVAL),
@@ -45,6 +46,7 @@ static const unsigned long kvm_isa_ext_arr[] = {
 	KVM_ISA_EXT_ARR(ZICBOM),
 	KVM_ISA_EXT_ARR(ZICBOZ),
 	KVM_ISA_EXT_ARR(ZICNTR),
+	KVM_ISA_EXT_ARR(ZICOND),
 	KVM_ISA_EXT_ARR(ZICSR),
 	KVM_ISA_EXT_ARR(ZIFENCEI),
 	KVM_ISA_EXT_ARR(ZIHINTPAUSE),
@@ -80,11 +82,11 @@ static bool kvm_riscv_vcpu_isa_enable_allowed(unsigned long ext)
 static bool kvm_riscv_vcpu_isa_disable_allowed(unsigned long ext)
 {
 	switch (ext) {
+	/* Extensions which don't have any mechanism to disable */
 	case KVM_RISCV_ISA_EXT_A:
 	case KVM_RISCV_ISA_EXT_C:
 	case KVM_RISCV_ISA_EXT_I:
 	case KVM_RISCV_ISA_EXT_M:
-	case KVM_RISCV_ISA_EXT_SSAIA:
 	case KVM_RISCV_ISA_EXT_SSTC:
 	case KVM_RISCV_ISA_EXT_SVINVAL:
 	case KVM_RISCV_ISA_EXT_SVNAPOT:
@@ -92,11 +94,15 @@ static bool kvm_riscv_vcpu_isa_disable_allowed(unsigned long ext)
 	case KVM_RISCV_ISA_EXT_ZBB:
 	case KVM_RISCV_ISA_EXT_ZBS:
 	case KVM_RISCV_ISA_EXT_ZICNTR:
+	case KVM_RISCV_ISA_EXT_ZICOND:
 	case KVM_RISCV_ISA_EXT_ZICSR:
 	case KVM_RISCV_ISA_EXT_ZIFENCEI:
 	case KVM_RISCV_ISA_EXT_ZIHINTPAUSE:
 	case KVM_RISCV_ISA_EXT_ZIHPM:
 		return false;
+	/* Extensions which can be disabled using Smstateen */
+	case KVM_RISCV_ISA_EXT_SSAIA:
+		return riscv_has_extension_unlikely(RISCV_ISA_EXT_SMSTATEEN);
 	default:
 		break;
 	}
@@ -378,6 +384,34 @@ static int kvm_riscv_vcpu_general_set_csr(struct kvm_vcpu *vcpu,
 	return 0;
 }
 
+static inline int kvm_riscv_vcpu_smstateen_set_csr(struct kvm_vcpu *vcpu,
+						   unsigned long reg_num,
+						   unsigned long reg_val)
+{
+	struct kvm_vcpu_smstateen_csr *csr = &vcpu->arch.smstateen_csr;
+
+	if (reg_num >= sizeof(struct kvm_riscv_smstateen_csr) /
+		sizeof(unsigned long))
+		return -EINVAL;
+
+	((unsigned long *)csr)[reg_num] = reg_val;
+	return 0;
+}
+
+static int kvm_riscv_vcpu_smstateen_get_csr(struct kvm_vcpu *vcpu,
+					    unsigned long reg_num,
+					    unsigned long *out_val)
+{
+	struct kvm_vcpu_smstateen_csr *csr = &vcpu->arch.smstateen_csr;
+
+	if (reg_num >= sizeof(struct kvm_riscv_smstateen_csr) /
+		sizeof(unsigned long))
+		return -EINVAL;
+
+	*out_val = ((unsigned long *)csr)[reg_num];
+	return 0;
+}
+
 static int kvm_riscv_vcpu_get_reg_csr(struct kvm_vcpu *vcpu,
 				      const struct kvm_one_reg *reg)
 {
@@ -401,6 +435,12 @@ static int kvm_riscv_vcpu_get_reg_csr(struct kvm_vcpu *vcpu,
 	case KVM_REG_RISCV_CSR_AIA:
 		rc = kvm_riscv_vcpu_aia_get_csr(vcpu, reg_num, &reg_val);
 		break;
+	case KVM_REG_RISCV_CSR_SMSTATEEN:
+		rc = -EINVAL;
+		if (riscv_has_extension_unlikely(RISCV_ISA_EXT_SMSTATEEN))
+			rc = kvm_riscv_vcpu_smstateen_get_csr(vcpu, reg_num,
+							      &reg_val);
+		break;
 	default:
 		rc = -ENOENT;
 		break;
@@ -440,6 +480,12 @@ static int kvm_riscv_vcpu_set_reg_csr(struct kvm_vcpu *vcpu,
 	case KVM_REG_RISCV_CSR_AIA:
 		rc = kvm_riscv_vcpu_aia_set_csr(vcpu, reg_num, reg_val);
 		break;
+	case KVM_REG_RISCV_CSR_SMSTATEEN:
+		rc = -EINVAL;
+		if (riscv_has_extension_unlikely(RISCV_ISA_EXT_SMSTATEEN))
+			rc = kvm_riscv_vcpu_smstateen_set_csr(vcpu, reg_num,
+							      reg_val);
+break;
 	default:
 		rc = -ENOENT;
 		break;
@@ -696,6 +742,8 @@ static inline unsigned long num_csr_regs(const struct kvm_vcpu *vcpu)
 
 	if (riscv_isa_extension_available(vcpu->arch.isa, SSAIA))
 		n += sizeof(struct kvm_riscv_aia_csr) / sizeof(unsigned long);
+	if (riscv_isa_extension_available(vcpu->arch.isa, SMSTATEEN))
+		n += sizeof(struct kvm_riscv_smstateen_csr) / sizeof(unsigned long);
 
 	return n;
 }
@@ -704,7 +752,7 @@ static int copy_csr_reg_indices(const struct kvm_vcpu *vcpu,
 				u64 __user *uindices)
 {
 	int n1 = sizeof(struct kvm_riscv_csr) / sizeof(unsigned long);
-	int n2 = 0;
+	int n2 = 0, n3 = 0;
 
 	/* copy general csr regs */
 	for (int i = 0; i < n1; i++) {
@@ -738,7 +786,25 @@ static int copy_csr_reg_indices(const struct kvm_vcpu *vcpu,
 		}
 	}
 
-	return n1 + n2;
+	/* copy Smstateen csr regs */
+	if (riscv_isa_extension_available(vcpu->arch.isa, SMSTATEEN)) {
+		n3 = sizeof(struct kvm_riscv_smstateen_csr) / sizeof(unsigned long);
+
+		for (int i = 0; i < n3; i++) {
+			u64 size = IS_ENABLED(CONFIG_32BIT) ?
+				   KVM_REG_SIZE_U32 : KVM_REG_SIZE_U64;
+			u64 reg = KVM_REG_RISCV | size | KVM_REG_RISCV_CSR |
+					  KVM_REG_RISCV_CSR_SMSTATEEN | i;
+
+			if (uindices) {
+				if (put_user(reg, uindices))
+					return -EFAULT;
+				uindices++;
+			}
+		}
+	}
+
+	return n1 + n2 + n3;
 }
 
 static inline unsigned long num_timer_regs(void)
diff --git a/arch/riscv/kvm/vcpu_sbi.c b/arch/riscv/kvm/vcpu_sbi.c
index 9cd97091c723..a04ff98085d9 100644
--- a/arch/riscv/kvm/vcpu_sbi.c
+++ b/arch/riscv/kvm/vcpu_sbi.c
@@ -67,6 +67,10 @@ static const struct kvm_riscv_sbi_extension_entry sbi_ext[] = {
 		.ext_ptr = &vcpu_sbi_ext_pmu,
 	},
 	{
+		.ext_idx = KVM_RISCV_SBI_EXT_DBCN,
+		.ext_ptr = &vcpu_sbi_ext_dbcn,
+	},
+	{
 		.ext_idx = KVM_RISCV_SBI_EXT_EXPERIMENTAL,
 		.ext_ptr = &vcpu_sbi_ext_experimental,
 	},
@@ -155,14 +159,8 @@ static int riscv_vcpu_set_sbi_ext_single(struct kvm_vcpu *vcpu,
 	if (!sext)
 		return -ENOENT;
 
-	/*
-	 * We can't set the extension status to available here, since it may
-	 * have a probe() function which needs to confirm availability first,
-	 * but it may be too early to call that here. We can set the status to
-	 * unavailable, though.
-	 */
-	if (!reg_val)
-		scontext->ext_status[sext->ext_idx] =
+	scontext->ext_status[sext->ext_idx] = (reg_val) ?
+			KVM_RISCV_SBI_EXT_AVAILABLE :
 			KVM_RISCV_SBI_EXT_UNAVAILABLE;
 
 	return 0;
@@ -188,16 +186,8 @@ static int riscv_vcpu_get_sbi_ext_single(struct kvm_vcpu *vcpu,
 	if (!sext)
 		return -ENOENT;
 
-	/*
-	 * If the extension status is still uninitialized, then we should probe
-	 * to determine if it's available, but it may be too early to do that
-	 * here. The best we can do is report that the extension has not been
-	 * disabled, i.e. we return 1 when the extension is available and also
-	 * when it only may be available.
-	 */
-	*reg_val = scontext->ext_status[sext->ext_idx] !=
-				KVM_RISCV_SBI_EXT_UNAVAILABLE;
-
+	*reg_val = scontext->ext_status[sext->ext_idx] ==
+				KVM_RISCV_SBI_EXT_AVAILABLE;
 	return 0;
 }
 
@@ -337,18 +327,8 @@ const struct kvm_vcpu_sbi_extension *kvm_vcpu_sbi_find_ext(
 			    scontext->ext_status[entry->ext_idx] ==
 						KVM_RISCV_SBI_EXT_AVAILABLE)
 				return ext;
-			if (scontext->ext_status[entry->ext_idx] ==
-						KVM_RISCV_SBI_EXT_UNAVAILABLE)
-				return NULL;
-			if (ext->probe && !ext->probe(vcpu)) {
-				scontext->ext_status[entry->ext_idx] =
-					KVM_RISCV_SBI_EXT_UNAVAILABLE;
-				return NULL;
-			}
 
-			scontext->ext_status[entry->ext_idx] =
-				KVM_RISCV_SBI_EXT_AVAILABLE;
-			return ext;
+			return NULL;
 		}
 	}
 
@@ -419,3 +399,26 @@ ecall_done:
 
 	return ret;
 }
+
+void kvm_riscv_vcpu_sbi_init(struct kvm_vcpu *vcpu)
+{
+	struct kvm_vcpu_sbi_context *scontext = &vcpu->arch.sbi_context;
+	const struct kvm_riscv_sbi_extension_entry *entry;
+	const struct kvm_vcpu_sbi_extension *ext;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(sbi_ext); i++) {
+		entry = &sbi_ext[i];
+		ext = entry->ext_ptr;
+
+		if (ext->probe && !ext->probe(vcpu)) {
+			scontext->ext_status[entry->ext_idx] =
+				KVM_RISCV_SBI_EXT_UNAVAILABLE;
+			continue;
+		}
+
+		scontext->ext_status[entry->ext_idx] = ext->default_unavail ?
+					KVM_RISCV_SBI_EXT_UNAVAILABLE :
+					KVM_RISCV_SBI_EXT_AVAILABLE;
+	}
+}
diff --git a/arch/riscv/kvm/vcpu_sbi_replace.c b/arch/riscv/kvm/vcpu_sbi_replace.c
index 7c4d5d38a339..23b57c931b15 100644
--- a/arch/riscv/kvm/vcpu_sbi_replace.c
+++ b/arch/riscv/kvm/vcpu_sbi_replace.c
@@ -175,3 +175,35 @@ const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_srst = {
 	.extid_end = SBI_EXT_SRST,
 	.handler = kvm_sbi_ext_srst_handler,
 };
+
+static int kvm_sbi_ext_dbcn_handler(struct kvm_vcpu *vcpu,
+				    struct kvm_run *run,
+				    struct kvm_vcpu_sbi_return *retdata)
+{
+	struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
+	unsigned long funcid = cp->a6;
+
+	switch (funcid) {
+	case SBI_EXT_DBCN_CONSOLE_WRITE:
+	case SBI_EXT_DBCN_CONSOLE_READ:
+	case SBI_EXT_DBCN_CONSOLE_WRITE_BYTE:
+		/*
+		 * The SBI debug console functions are unconditionally
+		 * forwarded to the userspace.
+		 */
+		kvm_riscv_vcpu_sbi_forward(vcpu, run);
+		retdata->uexit = true;
+		break;
+	default:
+		retdata->err_val = SBI_ERR_NOT_SUPPORTED;
+	}
+
+	return 0;
+}
+
+const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_dbcn = {
+	.extid_start = SBI_EXT_DBCN,
+	.extid_end = SBI_EXT_DBCN,
+	.default_unavail = true,
+	.handler = kvm_sbi_ext_dbcn_handler,
+};