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Re: [Qemu-devel] [PATCH 1/2] ppc: Add proper real mode translation suppo
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From: |
David Gibson |
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Subject: |
Re: [Qemu-devel] [PATCH 1/2] ppc: Add proper real mode translation support |
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Date: |
Wed, 29 Jun 2016 12:41:25 +1000 |
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User-agent: |
Mutt/1.6.1 (2016-04-27) |
On Tue, Jun 28, 2016 at 08:48:33AM +0200, Cédric Le Goater wrote:
> From: Benjamin Herrenschmidt <address@hidden>
>
> This adds proper support for translating real mode addresses based
> on the combination of HV and LPCR bits. This handles HRMOR offset
> for hypervisor real mode, and both RMA and VRMA modes for guest
> real mode. PAPR mode adjusts the offsets appropriately to match the
> RMA used in TCG, but we need to limit to the max supported by the
> implementation (16G).
>
> Signed-off-by: Benjamin Herrenschmidt <address@hidden>
> [clg: fixed checkpatch.pl errors ]
> Signed-off-by: Cédric Le Goater <address@hidden>
This looks correct and I've applied it. There are a couple of
possible cleanups which might be a good idea to follow up with though.
> ---
> hw/ppc/spapr.c | 7 +++
> target-ppc/mmu-hash64.c | 146
> ++++++++++++++++++++++++++++++++++++++------
> target-ppc/mmu-hash64.h | 1 +
> target-ppc/translate_init.c | 10 ++-
> 4 files changed, 144 insertions(+), 20 deletions(-)
>
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index d26b4c26ed10..53ab1f84fb11 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -1770,6 +1770,13 @@ static void ppc_spapr_init(MachineState *machine)
> spapr->vrma_adjust = 1;
> spapr->rma_size = MIN(spapr->rma_size, 0x10000000);
> }
> +
> + /* Actually we don't support unbounded RMA anymore since we
> + * added proper emulation of HV mode. The max we can get is
> + * 16G which also happens to be what we configure for PAPR
> + * mode so make sure we don't do anything bigger than that
> + */
> + spapr->rma_size = MIN(spapr->rma_size, 0x400000000ull);
#1 - Instead of the various KVM / non-KVM cases here, it might be
simpler to just always clamp the RMA to 256MiB.
> }
>
> if (spapr->rma_size > node0_size) {
> diff --git a/target-ppc/mmu-hash64.c b/target-ppc/mmu-hash64.c
> index 6d6f26c92957..ed353b2d1539 100644
> --- a/target-ppc/mmu-hash64.c
> +++ b/target-ppc/mmu-hash64.c
> @@ -653,13 +653,41 @@ static void ppc_hash64_set_dsi(CPUState *cs,
> CPUPPCState *env, uint64_t dar,
> env->error_code = 0;
> }
>
> +static int64_t ppc_hash64_get_rmls(CPUPPCState *env)
> +{
> + uint64_t lpcr = env->spr[SPR_LPCR];
> +
> + /*
> + * This is the full 4 bits encoding of POWER8. Previous
> + * CPUs only support a subset of these but the filtering
> + * is done when writing LPCR
> + */
> + switch ((lpcr & LPCR_RMLS) >> LPCR_RMLS_SHIFT) {
> + case 0x8: /* 32MB */
> + return 0x2000000ull;
> + case 0x3: /* 64MB */
> + return 0x4000000ull;
> + case 0x7: /* 128MB */
> + return 0x8000000ull;
> + case 0x4: /* 256MB */
> + return 0x10000000ull;
> + case 0x2: /* 1GB */
> + return 0x40000000ull;
> + case 0x1: /* 16GB */
> + return 0x400000000ull;
> + default:
> + /* What to do here ??? */
> + return 0;
> + }
> +}
>
> int ppc_hash64_handle_mmu_fault(PowerPCCPU *cpu, vaddr eaddr,
> int rwx, int mmu_idx)
> {
> CPUState *cs = CPU(cpu);
> CPUPPCState *env = &cpu->env;
> - ppc_slb_t *slb;
> + ppc_slb_t *slb_ptr;
> + ppc_slb_t slb;
> unsigned apshift;
> hwaddr pte_offset;
> ppc_hash_pte64_t pte;
> @@ -670,11 +698,53 @@ int ppc_hash64_handle_mmu_fault(PowerPCCPU *cpu, vaddr
> eaddr,
>
> assert((rwx == 0) || (rwx == 1) || (rwx == 2));
>
> + /* Note on LPCR usage: 970 uses HID4, but our special variant
> + * of store_spr copies relevant fields into env->spr[SPR_LPCR].
> + * Similarily we filter unimplemented bits when storing into
> + * LPCR depending on the MMU version. This code can thus just
> + * use the LPCR "as-is".
> + */
> +
> /* 1. Handle real mode accesses */
> if (((rwx == 2) && (msr_ir == 0)) || ((rwx != 2) && (msr_dr == 0))) {
> - /* Translation is off */
> - /* In real mode the top 4 effective address bits are ignored */
> + /* Translation is supposedly "off" */
> + /* In real mode the top 4 effective address bits are (mostly)
> ignored */
> raddr = eaddr & 0x0FFFFFFFFFFFFFFFULL;
> +
> + /* In HV mode, add HRMOR if top EA bit is clear */
> + if (msr_hv) {
> + if (!(eaddr >> 63)) {
> + raddr |= env->spr[SPR_HRMOR];
> + }
> + } else {
> + /* Otherwise, check VPM for RMA vs VRMA */
> + if (env->spr[SPR_LPCR] & LPCR_VPM0) {
> + uint32_t vrmasd;
> + /* VRMA, we make up an SLB entry */
> + slb.vsid = SLB_VSID_VRMA;
> + vrmasd = (env->spr[SPR_LPCR] & LPCR_VRMASD) >>
> + LPCR_VRMASD_SHIFT;
> + slb.vsid |= (vrmasd << 4) & (SLB_VSID_L | SLB_VSID_LP);
> + slb.esid = SLB_ESID_V;
> + goto skip_slb;
> + }
> + /* RMA. Check bounds in RMLS */
> + if (raddr < ppc_hash64_get_rmls(env)) {
> + raddr |= env->spr[SPR_RMOR];
> + } else {
> + /* The access failed, generate the approriate interrupt */
> + if (rwx == 2) {
> + ppc_hash64_set_isi(cs, env, 0x08000000);
> + } else {
> + dsisr = 0x08000000;
> + if (rwx == 1) {
> + dsisr |= 0x02000000;
> + }
> + ppc_hash64_set_dsi(cs, env, eaddr, dsisr);
> + }
> + return 1;
> + }
> + }
> tlb_set_page(cs, eaddr & TARGET_PAGE_MASK, raddr & TARGET_PAGE_MASK,
> PAGE_READ | PAGE_WRITE | PAGE_EXEC, mmu_idx,
> TARGET_PAGE_SIZE);
> @@ -682,9 +752,8 @@ int ppc_hash64_handle_mmu_fault(PowerPCCPU *cpu, vaddr
> eaddr,
> }
>
> /* 2. Translation is on, so look up the SLB */
> - slb = slb_lookup(cpu, eaddr);
> -
> - if (!slb) {
> + slb_ptr = slb_lookup(cpu, eaddr);
> + if (!slb_ptr) {
> if (rwx == 2) {
> cs->exception_index = POWERPC_EXCP_ISEG;
> env->error_code = 0;
> @@ -696,14 +765,29 @@ int ppc_hash64_handle_mmu_fault(PowerPCCPU *cpu, vaddr
> eaddr,
> return 1;
> }
>
> + /* We grab a local copy because we can modify it (or get a
> + * pre-cooked one from the VRMA code
> + */
> + slb = *slb_ptr;
> +
> + /* 2.5 Clamp L||LP in ISL mode */
> + if (env->spr[SPR_LPCR] & LPCR_ISL) {
> + slb.vsid &= ~SLB_VSID_LLP_MASK;
> + }
> +
> /* 3. Check for segment level no-execute violation */
> - if ((rwx == 2) && (slb->vsid & SLB_VSID_N)) {
> + if ((rwx == 2) && (slb.vsid & SLB_VSID_N)) {
> ppc_hash64_set_isi(cs, env, 0x10000000);
> return 1;
> }
>
> + /* We go straight here for VRMA translations as none of the
> + * above applies in that case
> + */
> + skip_slb:
> +
> /* 4. Locate the PTE in the hash table */
> - pte_offset = ppc_hash64_htab_lookup(cpu, slb, eaddr, &pte);
> + pte_offset = ppc_hash64_htab_lookup(cpu, &slb, eaddr, &pte);
> if (pte_offset == -1) {
> dsisr = 0x40000000;
> if (rwx == 2) {
> @@ -720,7 +804,7 @@ int ppc_hash64_handle_mmu_fault(PowerPCCPU *cpu, vaddr
> eaddr,
> "found PTE at offset %08" HWADDR_PRIx "\n", pte_offset);
>
> /* Validate page size encoding */
> - apshift = hpte_page_shift(slb->sps, pte.pte0, pte.pte1);
> + apshift = hpte_page_shift(slb.sps, pte.pte0, pte.pte1);
> if (!apshift) {
> error_report("Bad page size encoding in HPTE 0x%"PRIx64" - 0x%"PRIx64
> " @ 0x%"HWADDR_PRIx, pte.pte0, pte.pte1, pte_offset);
> @@ -733,7 +817,7 @@ int ppc_hash64_handle_mmu_fault(PowerPCCPU *cpu, vaddr
> eaddr,
>
> /* 5. Check access permissions */
>
> - pp_prot = ppc_hash64_pte_prot(cpu, slb, pte);
> + pp_prot = ppc_hash64_pte_prot(cpu, &slb, pte);
> amr_prot = ppc_hash64_amr_prot(cpu, pte);
> prot = pp_prot & amr_prot;
>
> @@ -789,27 +873,51 @@ int ppc_hash64_handle_mmu_fault(PowerPCCPU *cpu, vaddr
> eaddr,
> hwaddr ppc_hash64_get_phys_page_debug(PowerPCCPU *cpu, target_ulong addr)
> {
> CPUPPCState *env = &cpu->env;
> - ppc_slb_t *slb;
> - hwaddr pte_offset;
> + ppc_slb_t slb;
> + ppc_slb_t *slb_ptr;
> + hwaddr pte_offset, raddr;
> ppc_hash_pte64_t pte;
> unsigned apshift;
>
> + /* Handle real mode */
> if (msr_dr == 0) {
> - /* In real mode the top 4 effective address bits are ignored */
> - return addr & 0x0FFFFFFFFFFFFFFFULL;
> - }
> + raddr = addr & 0x0FFFFFFFFFFFFFFFULL;
>
> - slb = slb_lookup(cpu, addr);
> - if (!slb) {
> + /* In HV mode, add HRMOR if top EA bit is clear */
> + if (msr_hv & !(addr >> 63)) {
> + return raddr | env->spr[SPR_HRMOR];
> + }
> +
> + /* Otherwise, check VPM for RMA vs VRMA */
> + if (env->spr[SPR_LPCR] & LPCR_VPM0) {
> + uint32_t vrmasd;
> +
> + /* VRMA, we make up an SLB entry */
> + slb.vsid = SLB_VSID_VRMA;
> + vrmasd = (env->spr[SPR_LPCR] & LPCR_VRMASD) >> LPCR_VRMASD_SHIFT;
> + slb.vsid |= (vrmasd << 4) & (SLB_VSID_L | SLB_VSID_LP);
> + slb.esid = SLB_ESID_V;
> + goto skip_slb;
> + }
> + /* RMA. Check bounds in RMLS */
> + if (raddr < ppc_hash64_get_rmls(env)) {
> + return raddr | env->spr[SPR_RMOR];
> + }
Now that the real-mode case is non-trivial, it would be nice if we
could factor out some of this logic from the fault and page_debug
cases into a common helper function.
> return -1;
> }
>
> - pte_offset = ppc_hash64_htab_lookup(cpu, slb, addr, &pte);
> + slb_ptr = slb_lookup(cpu, addr);
> + if (!slb_ptr) {
> + return -1;
> + }
> + slb = *slb_ptr;
> + skip_slb:
> + pte_offset = ppc_hash64_htab_lookup(cpu, &slb, addr, &pte);
> if (pte_offset == -1) {
> return -1;
> }
>
> - apshift = hpte_page_shift(slb->sps, pte.pte0, pte.pte1);
> + apshift = hpte_page_shift(slb.sps, pte.pte0, pte.pte1);
> if (!apshift) {
> return -1;
> }
> diff --git a/target-ppc/mmu-hash64.h b/target-ppc/mmu-hash64.h
> index 6423b9f791e7..13ad060cfefb 100644
> --- a/target-ppc/mmu-hash64.h
> +++ b/target-ppc/mmu-hash64.h
> @@ -37,6 +37,7 @@ unsigned ppc_hash64_hpte_page_shift_noslb(PowerPCCPU *cpu,
> #define SLB_VSID_B_256M 0x0000000000000000ULL
> #define SLB_VSID_B_1T 0x4000000000000000ULL
> #define SLB_VSID_VSID 0x3FFFFFFFFFFFF000ULL
> +#define SLB_VSID_VRMA (0x0001FFFFFF000000ULL | SLB_VSID_B_1T)
> #define SLB_VSID_PTEM (SLB_VSID_B | SLB_VSID_VSID)
> #define SLB_VSID_KS 0x0000000000000800ULL
> #define SLB_VSID_KP 0x0000000000000400ULL
> diff --git a/target-ppc/translate_init.c b/target-ppc/translate_init.c
> index 55d1bfac97c4..4820c0bc99fb 100644
> --- a/target-ppc/translate_init.c
> +++ b/target-ppc/translate_init.c
> @@ -8791,11 +8791,19 @@ void cpu_ppc_set_papr(PowerPCCPU *cpu)
> /* Set emulated LPCR to not send interrupts to hypervisor. Note that
> * under KVM, the actual HW LPCR will be set differently by KVM itself,
> * the settings below ensure proper operations with TCG in absence of
> - * a real hypervisor
> + * a real hypervisor.
> + *
> + * Clearing VPM0 will also cause us to use RMOR in mmu-hash64.c for
> + * real mode accesses, which thankfully defaults to 0 and isn't
> + * accessible in guest mode.
> */
> lpcr->default_value &= ~(LPCR_VPM0 | LPCR_VPM1 | LPCR_ISL | LPCR_KBV);
> lpcr->default_value |= LPCR_LPES0 | LPCR_LPES1;
>
> + /* Set RMLS to the max (ie, 16G) */
> + lpcr->default_value &= ~LPCR_RMLS;
> + lpcr->default_value |= 1ull << LPCR_RMLS_SHIFT;
> +
> /* P7 and P8 has slightly different PECE bits, mostly because P8 adds
> * bit 47 and 48 which are reserved on P7. Here we set them all, which
> * will work as expected for both implementations
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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