nfs: disintegrate UAPI for nfs

This is to complete part of the Userspace API (UAPI) disintegration for which
the preparatory patches were pulled recently.  After these patches, userspace
headers will be segregated into:

        include/uapi/linux/.../foo.h

for the userspace interface stuff, and:

        include/linux/.../foo.h

for the strictly kernel internal stuff.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

4 files changed, 133 insertions, 20 deletions

diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index bf33aaa4c59f..f6ec3a92e621 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -857,7 +857,8 @@ struct kvm_userspace_memory_region {
 };
 
 /* for kvm_memory_region::flags */
-#define KVM_MEM_LOG_DIRTY_PAGES  1UL
+#define KVM_MEM_LOG_DIRTY_PAGES	(1UL << 0)
+#define KVM_MEM_READONLY	(1UL << 1)
 
 This ioctl allows the user to create or modify a guest physical memory
 slot.  When changing an existing slot, it may be moved in the guest
@@ -873,14 +874,17 @@ It is recommended that the lower 21 bits of guest_phys_addr and userspace_addr
 be identical.  This allows large pages in the guest to be backed by large
 pages in the host.
 
-The flags field supports just one flag, KVM_MEM_LOG_DIRTY_PAGES, which
-instructs kvm to keep track of writes to memory within the slot.  See
-the KVM_GET_DIRTY_LOG ioctl.
+The flags field supports two flag, KVM_MEM_LOG_DIRTY_PAGES, which instructs
+kvm to keep track of writes to memory within the slot.  See KVM_GET_DIRTY_LOG
+ioctl.  The KVM_CAP_READONLY_MEM capability indicates the availability of the
+KVM_MEM_READONLY flag.  When this flag is set for a memory region, KVM only
+allows read accesses.  Writes will be posted to userspace as KVM_EXIT_MMIO
+exits.
 
-When the KVM_CAP_SYNC_MMU capability, changes in the backing of the memory
-region are automatically reflected into the guest.  For example, an mmap()
-that affects the region will be made visible immediately.  Another example
-is madvise(MADV_DROP).
+When the KVM_CAP_SYNC_MMU capability is available, changes in the backing of
+the memory region are automatically reflected into the guest.  For example, an
+mmap() that affects the region will be made visible immediately.  Another
+example is madvise(MADV_DROP).
 
 It is recommended to use this API instead of the KVM_SET_MEMORY_REGION ioctl.
 The KVM_SET_MEMORY_REGION does not allow fine grained control over memory
@@ -1946,6 +1950,19 @@ the guest using the specified gsi pin.  The irqfd is removed using
 the KVM_IRQFD_FLAG_DEASSIGN flag, specifying both kvm_irqfd.fd
 and kvm_irqfd.gsi.
 
+With KVM_CAP_IRQFD_RESAMPLE, KVM_IRQFD supports a de-assert and notify
+mechanism allowing emulation of level-triggered, irqfd-based
+interrupts.  When KVM_IRQFD_FLAG_RESAMPLE is set the user must pass an
+additional eventfd in the kvm_irqfd.resamplefd field.  When operating
+in resample mode, posting of an interrupt through kvm_irq.fd asserts
+the specified gsi in the irqchip.  When the irqchip is resampled, such
+as from an EOI, the gsi is de-asserted and the user is notifed via
+kvm_irqfd.resamplefd.  It is the user's responsibility to re-queue
+the interrupt if the device making use of it still requires service.
+Note that closing the resamplefd is not sufficient to disable the
+irqfd.  The KVM_IRQFD_FLAG_RESAMPLE is only necessary on assignment
+and need not be specified with KVM_IRQFD_FLAG_DEASSIGN.
+
 4.76 KVM_PPC_ALLOCATE_HTAB
 
 Capability: KVM_CAP_PPC_ALLOC_HTAB
diff --git a/Documentation/virtual/kvm/hypercalls.txt b/Documentation/virtual/kvm/hypercalls.txt
new file mode 100644
index 000000000000..ea113b5d87a4
--- /dev/null
+++ b/Documentation/virtual/kvm/hypercalls.txt
@@ -0,0 +1,66 @@
+Linux KVM Hypercall:
+===================
+X86:
+ KVM Hypercalls have a three-byte sequence of either the vmcall or the vmmcall
+ instruction. The hypervisor can replace it with instructions that are
+ guaranteed to be supported.
+
+ Up to four arguments may be passed in rbx, rcx, rdx, and rsi respectively.
+ The hypercall number should be placed in rax and the return value will be
+ placed in rax.  No other registers will be clobbered unless explicitly stated
+ by the particular hypercall.
+
+S390:
+  R2-R7 are used for parameters 1-6. In addition, R1 is used for hypercall
+  number. The return value is written to R2.
+
+  S390 uses diagnose instruction as hypercall (0x500) along with hypercall
+  number in R1.
+
+ PowerPC:
+  It uses R3-R10 and hypercall number in R11. R4-R11 are used as output registers.
+  Return value is placed in R3.
+
+  KVM hypercalls uses 4 byte opcode, that are patched with 'hypercall-instructions'
+  property inside the device tree's /hypervisor node.
+  For more information refer to Documentation/virtual/kvm/ppc-pv.txt
+
+KVM Hypercalls Documentation
+===========================
+The template for each hypercall is:
+1. Hypercall name.
+2. Architecture(s)
+3. Status (deprecated, obsolete, active)
+4. Purpose
+
+1. KVM_HC_VAPIC_POLL_IRQ
+------------------------
+Architecture: x86
+Status: active
+Purpose: Trigger guest exit so that the host can check for pending
+interrupts on reentry.
+
+2. KVM_HC_MMU_OP
+------------------------
+Architecture: x86
+Status: deprecated.
+Purpose: Support MMU operations such as writing to PTE,
+flushing TLB, release PT.
+
+3. KVM_HC_FEATURES
+------------------------
+Architecture: PPC
+Status: active
+Purpose: Expose hypercall availability to the guest. On x86 platforms, cpuid
+used to enumerate which hypercalls are available. On PPC, either device tree
+based lookup ( which is also what EPAPR dictates) OR KVM specific enumeration
+mechanism (which is this hypercall) can be used.
+
+4. KVM_HC_PPC_MAP_MAGIC_PAGE
+------------------------
+Architecture: PPC
+Status: active
+Purpose: To enable communication between the hypervisor and guest there is a
+shared page that contains parts of supervisor visible register state.
+The guest can map this shared page to access its supervisor register through
+memory using this hypercall.
diff --git a/Documentation/virtual/kvm/msr.txt b/Documentation/virtual/kvm/msr.txt
index 730471048583..6d470ae7b073 100644
--- a/Documentation/virtual/kvm/msr.txt
+++ b/Documentation/virtual/kvm/msr.txt
@@ -34,9 +34,12 @@ MSR_KVM_WALL_CLOCK_NEW:   0x4b564d00
 		time information and check that they are both equal and even.
 		An odd version indicates an in-progress update.
 
-		sec: number of seconds for wallclock.
+		sec: number of seconds for wallclock at time of boot.
 
-		nsec: number of nanoseconds for wallclock.
+		nsec: number of nanoseconds for wallclock at time of boot.
+
+	In order to get the current wallclock time, the system_time from
+	MSR_KVM_SYSTEM_TIME_NEW needs to be added.
 
 	Note that although MSRs are per-CPU entities, the effect of this
 	particular MSR is global.
@@ -82,20 +85,25 @@ MSR_KVM_SYSTEM_TIME_NEW:  0x4b564d01
 		time at the time this structure was last updated. Unit is
 		nanoseconds.
 
-		tsc_to_system_mul: a function of the tsc frequency. One has
-		to multiply any tsc-related quantity by this value to get
-		a value in nanoseconds, besides dividing by 2^tsc_shift
+		tsc_to_system_mul: multiplier to be used when converting
+		tsc-related quantity to nanoseconds
 
-		tsc_shift: cycle to nanosecond divider, as a power of two, to
-		allow for shift rights. One has to shift right any tsc-related
-		quantity by this value to get a value in nanoseconds, besides
-		multiplying by tsc_to_system_mul.
+		tsc_shift: shift to be used when converting tsc-related
+		quantity to nanoseconds. This shift will ensure that
+		multiplication with tsc_to_system_mul does not overflow.
+		A positive value denotes a left shift, a negative value
+		a right shift.
 
-		With this information, guests can derive per-CPU time by
-		doing:
+		The conversion from tsc to nanoseconds involves an additional
+		right shift by 32 bits. With this information, guests can
+		derive per-CPU time by doing:
 
 			time = (current_tsc - tsc_timestamp)
-			time = (time * tsc_to_system_mul) >> tsc_shift
+			if (tsc_shift >= 0)
+				time <<= tsc_shift;
+			else
+				time >>= -tsc_shift;
+			time = (time * tsc_to_system_mul) >> 32
 			time = time + system_time
 
 		flags: bits in this field indicate extended capabilities
diff --git a/Documentation/virtual/kvm/ppc-pv.txt b/Documentation/virtual/kvm/ppc-pv.txt
index 4911cf95c67e..4cd076febb02 100644
--- a/Documentation/virtual/kvm/ppc-pv.txt
+++ b/Documentation/virtual/kvm/ppc-pv.txt
@@ -174,3 +174,25 @@ following:
 That way we can inject an arbitrary amount of code as replacement for a single
 instruction. This allows us to check for pending interrupts when setting EE=1
 for example.
+
+Hypercall ABIs in KVM on PowerPC
+=================================
+1) KVM hypercalls (ePAPR)
+
+These are ePAPR compliant hypercall implementation (mentioned above). Even
+generic hypercalls are implemented here, like the ePAPR idle hcall. These are
+available on all targets.
+
+2) PAPR hypercalls
+
+PAPR hypercalls are needed to run server PowerPC PAPR guests (-M pseries in QEMU).
+These are the same hypercalls that pHyp, the POWER hypervisor implements. Some of
+them are handled in the kernel, some are handled in user space. This is only
+available on book3s_64.
+
+3) OSI hypercalls
+
+Mac-on-Linux is another user of KVM on PowerPC, which has its own hypercall (long
+before KVM). This is supported to maintain compatibility. All these hypercalls get
+forwarded to user space. This is only useful on book3s_32, but can be used with
+book3s_64 as well.