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

Pull kvm updates from Paolo Bonzini:
 "S390:

   - Changes to FPU handling came in via the main s390 pull request

   - Only deliver to the guest the SCLP events that userspace has
     requested

   - More virtual vs physical address fixes (only a cleanup since
     virtual and physical address spaces are currently the same)

   - Fix selftests undefined behavior

  x86:

   - Fix a restriction that the guest can't program a PMU event whose
     encoding matches an architectural event that isn't included in the
     guest CPUID. The enumeration of an architectural event only says
     that if a CPU supports an architectural event, then the event can
     be programmed *using the architectural encoding*. The enumeration
     does NOT say anything about the encoding when the CPU doesn't
     report support the event *in general*. It might support it, and it
     might support it using the same encoding that made it into the
     architectural PMU spec

   - Fix a variety of bugs in KVM's emulation of RDPMC (more details on
     individual commits) and add a selftest to verify KVM correctly
     emulates RDMPC, counter availability, and a variety of other
     PMC-related behaviors that depend on guest CPUID and therefore are
     easier to validate with selftests than with custom guests (aka
     kvm-unit-tests)

   - Zero out PMU state on AMD if the virtual PMU is disabled, it does
     not cause any bug but it wastes time in various cases where KVM
     would check if a PMC event needs to be synthesized

   - Optimize triggering of emulated events, with a nice ~10%
     performance improvement in VM-Exit microbenchmarks when a vPMU is
     exposed to the guest

   - Tighten the check for "PMI in guest" to reduce false positives if
     an NMI arrives in the host while KVM is handling an IRQ VM-Exit

   - Fix a bug where KVM would report stale/bogus exit qualification
     information when exiting to userspace with an internal error exit
     code

   - Add a VMX flag in /proc/cpuinfo to report 5-level EPT support

   - Rework TDP MMU root unload, free, and alloc to run with mmu_lock
     held for read, e.g. to avoid serializing vCPUs when userspace
     deletes a memslot

   - Tear down TDP MMU page tables at 4KiB granularity (used to be
     1GiB). KVM doesn't support yielding in the middle of processing a
     zap, and 1GiB granularity resulted in multi-millisecond lags that
     are quite impolite for CONFIG_PREEMPT kernels

   - Allocate write-tracking metadata on-demand to avoid the memory
     overhead when a kernel is built with i915 virtualization support
     but the workloads use neither shadow paging nor i915 virtualization

   - Explicitly initialize a variety of on-stack variables in the
     emulator that triggered KMSAN false positives

   - Fix the debugregs ABI for 32-bit KVM

   - Rework the "force immediate exit" code so that vendor code
     ultimately decides how and when to force the exit, which allowed
     some optimization for both Intel and AMD

   - Fix a long-standing bug where kvm_has_noapic_vcpu could be left
     elevated if vCPU creation ultimately failed, causing extra
     unnecessary work

   - Cleanup the logic for checking if the currently loaded vCPU is
     in-kernel

   - Harden against underflowing the active mmu_notifier invalidation
     count, so that "bad" invalidations (usually due to bugs elsehwere
     in the kernel) are detected earlier and are less likely to hang the
     kernel

  x86 Xen emulation:

   - Overlay pages can now be cached based on host virtual address,
     instead of guest physical addresses. This removes the need to
     reconfigure and invalidate the cache if the guest changes the gpa
     but the underlying host virtual address remains the same

   - When possible, use a single host TSC value when computing the
     deadline for Xen timers in order to improve the accuracy of the
     timer emulation

   - Inject pending upcall events when the vCPU software-enables its
     APIC to fix a bug where an upcall can be lost (and to follow Xen's
     behavior)

   - Fall back to the slow path instead of warning if "fast" IRQ
     delivery of Xen events fails, e.g. if the guest has aliased xAPIC
     IDs

  RISC-V:

   - Support exception and interrupt handling in selftests

   - New self test for RISC-V architectural timer (Sstc extension)

   - New extension support (Ztso, Zacas)

   - Support userspace emulation of random number seed CSRs

  ARM:

   - Infrastructure for building KVM's trap configuration based on the
     architectural features (or lack thereof) advertised in the VM's ID
     registers

   - Support for mapping vfio-pci BARs as Normal-NC (vaguely similar to
     x86's WC) at stage-2, improving the performance of interacting with
     assigned devices that can tolerate it

   - Conversion of KVM's representation of LPIs to an xarray, utilized
     to address serialization some of the serialization on the LPI
     injection path

   - Support for _architectural_ VHE-only systems, advertised through
     the absence of FEAT_E2H0 in the CPU's ID register

   - Miscellaneous cleanups, fixes, and spelling corrections to KVM and
     selftests

  LoongArch:

   - Set reserved bits as zero in CPUCFG

   - Start SW timer only when vcpu is blocking

   - Do not restart SW timer when it is expired

   - Remove unnecessary CSR register saving during enter guest

   - Misc cleanups and fixes as usual

  Generic:

   - Clean up Kconfig by removing CONFIG_HAVE_KVM, which was basically
     always true on all architectures except MIPS (where Kconfig
     determines the available depending on CPU capabilities). It is
     replaced either by an architecture-dependent symbol for MIPS, and
     IS_ENABLED(CONFIG_KVM) everywhere else

   - Factor common "select" statements in common code instead of
     requiring each architecture to specify it

   - Remove thoroughly obsolete APIs from the uapi headers

   - Move architecture-dependent stuff to uapi/asm/kvm.h

   - Always flush the async page fault workqueue when a work item is
     being removed, especially during vCPU destruction, to ensure that
     there are no workers running in KVM code when all references to
     KVM-the-module are gone, i.e. to prevent a very unlikely
     use-after-free if kvm.ko is unloaded

   - Grab a reference to the VM's mm_struct in the async #PF worker
     itself instead of gifting the worker a reference, so that there's
     no need to remember to *conditionally* clean up after the worker

  Selftests:

   - Reduce boilerplate especially when utilize selftest TAP
     infrastructure

   - Add basic smoke tests for SEV and SEV-ES, along with a pile of
     library support for handling private/encrypted/protected memory

   - Fix benign bugs where tests neglect to close() guest_memfd files"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (246 commits)
  selftests: kvm: remove meaningless assignments in Makefiles
  KVM: riscv: selftests: Add Zacas extension to get-reg-list test
  RISC-V: KVM: Allow Zacas extension for Guest/VM
  KVM: riscv: selftests: Add Ztso extension to get-reg-list test
  RISC-V: KVM: Allow Ztso extension for Guest/VM
  RISC-V: KVM: Forward SEED CSR access to user space
  KVM: riscv: selftests: Add sstc timer test
  KVM: riscv: selftests: Change vcpu_has_ext to a common function
  KVM: riscv: selftests: Add guest helper to get vcpu id
  KVM: riscv: selftests: Add exception handling support
  LoongArch: KVM: Remove unnecessary CSR register saving during enter guest
  LoongArch: KVM: Do not restart SW timer when it is expired
  LoongArch: KVM: Start SW timer only when vcpu is blocking
  LoongArch: KVM: Set reserved bits as zero in CPUCFG
  KVM: selftests: Explicitly close guest_memfd files in some gmem tests
  KVM: x86/xen: fix recursive deadlock in timer injection
  KVM: pfncache: simplify locking and make more self-contained
  KVM: x86/xen: remove WARN_ON_ONCE() with false positives in evtchn delivery
  KVM: x86/xen: inject vCPU upcall vector when local APIC is enabled
  KVM: x86/xen: improve accuracy of Xen timers
  ...

6 files changed, 37 insertions, 50 deletions

diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
index b274784c2e26..c139d0d72802 100644
--- a/arch/loongarch/Kconfig
+++ b/arch/loongarch/Kconfig
@@ -133,7 +133,6 @@ config LOONGARCH
 	select HAVE_KPROBES
 	select HAVE_KPROBES_ON_FTRACE
 	select HAVE_KRETPROBES
-	select HAVE_KVM
 	select HAVE_MOD_ARCH_SPECIFIC
 	select HAVE_NMI
 	select HAVE_PCI
diff --git a/arch/loongarch/include/uapi/asm/kvm.h b/arch/loongarch/include/uapi/asm/kvm.h
index 923d0bd38294..109785922cf9 100644
--- a/arch/loongarch/include/uapi/asm/kvm.h
+++ b/arch/loongarch/include/uapi/asm/kvm.h
@@ -14,8 +14,6 @@
  * Some parts derived from the x86 version of this file.
  */
 
-#define __KVM_HAVE_READONLY_MEM
-
 #define KVM_COALESCED_MMIO_PAGE_OFFSET	1
 #define KVM_DIRTY_LOG_PAGE_OFFSET	64
 
diff --git a/arch/loongarch/kvm/Kconfig b/arch/loongarch/kvm/Kconfig
index 61f7e33b1f95..c4ef2b4d9797 100644
--- a/arch/loongarch/kvm/Kconfig
+++ b/arch/loongarch/kvm/Kconfig
@@ -20,7 +20,6 @@ if VIRTUALIZATION
 config KVM
 	tristate "Kernel-based Virtual Machine (KVM) support"
 	depends on AS_HAS_LVZ_EXTENSION
-	depends on HAVE_KVM
 	select HAVE_KVM_DIRTY_RING_ACQ_REL
 	select HAVE_KVM_VCPU_ASYNC_IOCTL
 	select KVM_COMMON
@@ -28,6 +27,7 @@ config KVM
 	select KVM_GENERIC_HARDWARE_ENABLING
 	select KVM_GENERIC_MMU_NOTIFIER
 	select KVM_MMIO
+	select HAVE_KVM_READONLY_MEM
 	select KVM_XFER_TO_GUEST_WORK
 	help
 	  Support hosting virtualized guest machines using
diff --git a/arch/loongarch/kvm/switch.S b/arch/loongarch/kvm/switch.S
index ba976509bfe8..3634431db18a 100644
--- a/arch/loongarch/kvm/switch.S
+++ b/arch/loongarch/kvm/switch.S
@@ -213,12 +213,6 @@ SYM_FUNC_START(kvm_enter_guest)
 	/* Save host GPRs */
 	kvm_save_host_gpr a2
 
-	/* Save host CRMD, PRMD to stack */
-	csrrd	a3, LOONGARCH_CSR_CRMD
-	st.d	a3, a2, PT_CRMD
-	csrrd	a3, LOONGARCH_CSR_PRMD
-	st.d	a3, a2, PT_PRMD
-
 	addi.d	a2, a1, KVM_VCPU_ARCH
 	st.d	sp, a2, KVM_ARCH_HSP
 	st.d	tp, a2, KVM_ARCH_HTP
diff --git a/arch/loongarch/kvm/timer.c b/arch/loongarch/kvm/timer.c
index 111328f60872..bcc6b6d063d9 100644
--- a/arch/loongarch/kvm/timer.c
+++ b/arch/loongarch/kvm/timer.c
@@ -23,24 +23,6 @@ static inline u64 tick_to_ns(struct kvm_vcpu *vcpu, u64 tick)
 	return div_u64(tick * MNSEC_PER_SEC, vcpu->arch.timer_mhz);
 }
 
-/*
- * Push timer forward on timeout.
- * Handle an hrtimer event by push the hrtimer forward a period.
- */
-static enum hrtimer_restart kvm_count_timeout(struct kvm_vcpu *vcpu)
-{
-	unsigned long cfg, period;
-
-	/* Add periodic tick to current expire time */
-	cfg = kvm_read_sw_gcsr(vcpu->arch.csr, LOONGARCH_CSR_TCFG);
-	if (cfg & CSR_TCFG_PERIOD) {
-		period = tick_to_ns(vcpu, cfg & CSR_TCFG_VAL);
-		hrtimer_add_expires_ns(&vcpu->arch.swtimer, period);
-		return HRTIMER_RESTART;
-	} else
-		return HRTIMER_NORESTART;
-}
-
 /* Low level hrtimer wake routine */
 enum hrtimer_restart kvm_swtimer_wakeup(struct hrtimer *timer)
 {
@@ -50,7 +32,7 @@ enum hrtimer_restart kvm_swtimer_wakeup(struct hrtimer *timer)
 	kvm_queue_irq(vcpu, INT_TI);
 	rcuwait_wake_up(&vcpu->wait);
 
-	return kvm_count_timeout(vcpu);
+	return HRTIMER_NORESTART;
 }
 
 /*
@@ -93,7 +75,8 @@ void kvm_restore_timer(struct kvm_vcpu *vcpu)
 	/*
 	 * Freeze the soft-timer and sync the guest stable timer with it.
 	 */
-	hrtimer_cancel(&vcpu->arch.swtimer);
+	if (kvm_vcpu_is_blocking(vcpu))
+		hrtimer_cancel(&vcpu->arch.swtimer);
 
 	/*
 	 * From LoongArch Reference Manual Volume 1 Chapter 7.6.2
@@ -168,26 +151,20 @@ static void _kvm_save_timer(struct kvm_vcpu *vcpu)
 	 * Here judge one-shot timer fired by checking whether TVAL is larger
 	 * than TCFG
 	 */
-	if (ticks < cfg) {
+	if (ticks < cfg)
 		delta = tick_to_ns(vcpu, ticks);
-		expire = ktime_add_ns(ktime_get(), delta);
-		vcpu->arch.expire = expire;
+	else
+		delta = 0;
+
+	expire = ktime_add_ns(ktime_get(), delta);
+	vcpu->arch.expire = expire;
+	if (kvm_vcpu_is_blocking(vcpu)) {
 
 		/*
 		 * HRTIMER_MODE_PINNED is suggested since vcpu may run in
 		 * the same physical cpu in next time
 		 */
 		hrtimer_start(&vcpu->arch.swtimer, expire, HRTIMER_MODE_ABS_PINNED);
-	} else if (vcpu->stat.generic.blocking) {
-		/*
-		 * Inject timer interrupt so that halt polling can dectect and exit.
-		 * VCPU is scheduled out already and sleeps in rcuwait queue and
-		 * will not poll pending events again. kvm_queue_irq() is not enough,
-		 * hrtimer swtimer should be used here.
-		 */
-		expire = ktime_add_ns(ktime_get(), 10);
-		vcpu->arch.expire = expire;
-		hrtimer_start(&vcpu->arch.swtimer, expire, HRTIMER_MODE_ABS_PINNED);
 	}
 }
 
diff --git a/arch/loongarch/kvm/vcpu.c b/arch/loongarch/kvm/vcpu.c
index 36106922b5d7..3a8779065f73 100644
--- a/arch/loongarch/kvm/vcpu.c
+++ b/arch/loongarch/kvm/vcpu.c
@@ -304,11 +304,18 @@ static int _kvm_get_cpucfg_mask(int id, u64 *v)
 		return -EINVAL;
 
 	switch (id) {
-	case 2:
+	case LOONGARCH_CPUCFG0:
+		*v = GENMASK(31, 0);
+		return 0;
+	case LOONGARCH_CPUCFG1:
+		/* CPUCFG1_MSGINT is not supported by KVM */
+		*v = GENMASK(25, 0);
+		return 0;
+	case LOONGARCH_CPUCFG2:
 		/* CPUCFG2 features unconditionally supported by KVM */
 		*v = CPUCFG2_FP     | CPUCFG2_FPSP  | CPUCFG2_FPDP     |
 		     CPUCFG2_FPVERS | CPUCFG2_LLFTP | CPUCFG2_LLFTPREV |
-		     CPUCFG2_LAM;
+		     CPUCFG2_LSPW | CPUCFG2_LAM;
 		/*
 		 * For the ISA extensions listed below, if one is supported
 		 * by the host, then it is also supported by KVM.
@@ -319,13 +326,25 @@ static int _kvm_get_cpucfg_mask(int id, u64 *v)
 			*v |= CPUCFG2_LASX;
 
 		return 0;
+	case LOONGARCH_CPUCFG3:
+		*v = GENMASK(16, 0);
+		return 0;
+	case LOONGARCH_CPUCFG4:
+	case LOONGARCH_CPUCFG5:
+		*v = GENMASK(31, 0);
+		return 0;
+	case LOONGARCH_CPUCFG16:
+		*v = GENMASK(16, 0);
+		return 0;
+	case LOONGARCH_CPUCFG17 ... LOONGARCH_CPUCFG20:
+		*v = GENMASK(30, 0);
+		return 0;
 	default:
 		/*
-		 * No restrictions on other valid CPUCFG IDs' values, but
-		 * CPUCFG data is limited to 32 bits as the LoongArch ISA
-		 * manual says (Volume 1, Section 2.2.10.5 "CPUCFG").
+		 * CPUCFG bits should be zero if reserved by HW or not
+		 * supported by KVM.
 		 */
-		*v = U32_MAX;
+		*v = 0;
 		return 0;
 	}
 }
@@ -344,7 +363,7 @@ static int kvm_check_cpucfg(int id, u64 val)
 		return -EINVAL;
 
 	switch (id) {
-	case 2:
+	case LOONGARCH_CPUCFG2:
 		if (!(val & CPUCFG2_LLFTP))
 			/* Guests must have a constant timer */
 			return -EINVAL;