Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 31 insertions, 0 deletions

diff --git a/arch/mips/kvm/00README.txt b/arch/mips/kvm/00README.txt
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+KVM/MIPS Trap & Emulate Release Notes
+=====================================
+
+(1) KVM/MIPS should support MIPS32R2 and beyond. It has been tested on the following platforms:
+    Malta Board with FPGA based 34K
+    Sigma Designs TangoX board with a 24K based 8654 SoC.
+    Malta Board with 74K @ 1GHz
+
+(2) Both Guest kernel and Guest Userspace execute in UM.
+    Guest User address space:   0x00000000 -> 0x40000000
+    Guest Kernel Unmapped:      0x40000000 -> 0x60000000
+    Guest Kernel Mapped:        0x60000000 -> 0x80000000
+
+    Guest Usermode virtual memory is limited to 1GB.
+
+(2) 16K Page Sizes: Both Host Kernel and Guest Kernel should have the same page size, currently at least 16K.
+    Note that due to cache aliasing issues, 4K page sizes are NOT supported.
+
+(3) No HugeTLB Support
+    Both the host kernel and Guest kernel should have the page size set to 16K.
+    This will be implemented in a future release.
+
+(4) KVM/MIPS does not have support for SMP Guests
+    Linux-3.7-rc2 based SMP guest hangs due to the following code sequence in the generated TLB handlers:
+	LL/TLBP/SC.  Since the TLBP instruction causes a trap the reservation gets cleared
+	when we ERET back to the guest. This causes the guest to hang in an infinite loop.
+	This will be fixed in a future release.
+
+(5) Use Host FPU
+    Currently KVM/MIPS emulates a 24K CPU without a FPU.
+    This will be fixed in a future release