qemu/pc-bios/bios-pq/0008_kvm-bios-switch-mtrrs-to-cover-only-the-pci-range-and--default-to-wb.patch
aliguori 9a717b55df Add BIOS fixes from KVM tree
See each patch for individual Signed-off-by's/commit logs



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6392 c046a42c-6fe2-441c-8c8c-71466251a162
2009-01-21 21:46:20 +00:00

55 lines
1.9 KiB
Diff

switch MTRRs to cover only the PCI range and default to WB (Alex Williamson)
This matches how some bare metal machines report MTRRs and avoids
the problem of running out of MTRRs to cover all of RAM.
Signed-off-by: Alex Williamson <alex.williamson@hp.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Index: bochs/bios/rombios32.c
===================================================================
--- bochs.orig/bios/rombios32.c
+++ bochs/bios/rombios32.c
@@ -525,7 +525,6 @@ void setup_mtrr(void)
uint8_t valb[8];
uint64_t val;
} u;
- uint64_t vbase, vmask;
mtrr_cap = rdmsr(MSR_MTRRcap);
vcnt = mtrr_cap & 0xff;
@@ -552,25 +551,10 @@ void setup_mtrr(void)
wrmsr_smp(MSR_MTRRfix4K_E8000, 0);
wrmsr_smp(MSR_MTRRfix4K_F0000, 0);
wrmsr_smp(MSR_MTRRfix4K_F8000, 0);
- vbase = 0;
- --vcnt; /* leave one mtrr for VRAM */
- for (i = 0; i < vcnt && vbase < ram_size; ++i) {
- vmask = (1ull << 40) - 1;
- while (vbase + vmask + 1 > ram_size)
- vmask >>= 1;
- wrmsr_smp(MTRRphysBase_MSR(i), vbase | 6);
- wrmsr_smp(MTRRphysMask_MSR(i), (~vmask & 0xfffffff000ull) | 0x800);
- vbase += vmask + 1;
- }
- for (vbase = 1ull << 32; i < vcnt && vbase < ram_end; ++i) {
- vmask = (1ull << 40) - 1;
- while (vbase + vmask + 1 > ram_end)
- vmask >>= 1;
- wrmsr_smp(MTRRphysBase_MSR(i), vbase | 6);
- wrmsr_smp(MTRRphysMask_MSR(i), (~vmask & 0xfffffff000ull) | 0x800);
- vbase += vmask + 1;
- }
- wrmsr_smp(MSR_MTRRdefType, 0xc00);
+ /* Mark 3.5-4GB as UC, anything not specified defaults to WB */
+ wrmsr_smp(MTRRphysBase_MSR(0), 0xe0000000ull | 0);
+ wrmsr_smp(MTRRphysMask_MSR(0), ~(0x20000000ull - 1) | 0x800);
+ wrmsr_smp(MSR_MTRRdefType, 0xc06);
}
void ram_probe(void)